Peak Summer Transport Strategies for the Chamonix Valley

TL;DR: Peak Summer Transport Strategies for the Chamonix Valley

Navigating the Chamonix Valley during the peak 2026 summer season demands abandoning personal vehicles in favour of pre-engineered transit networks. The valley floor operates under extreme demographic pressure, rendering the primary highway chronically gridlocked. High-efficiency ingress relies exclusively on securing a direct Alps2Alps transfer from Geneva Airport, ensuring heavy alpine equipment and technical gear bypass standard public transport bottlenecks and reach base camp without manual hauling.

Intra-valley mobility relies entirely on the municipal Carte d’Hôte, granting unrestricted access to the Chamonix Mobilité bus fleet and the Mont Blanc Express railway. Combining this local transit infrastructure with a pre-purchased Mont Blanc MultiPass secures immediate, frictionless access to the high-altitude lift network. Adhering to these structured transport protocols and mandatory digital reservation systems remains the only viable method for executing high-volume alpine objectives while bypassing severe summer congestion.

Defining Peak Summer Transport in the Chamonix Valley

The Structural Realities of High-Season Alpine Mobility

Peak summer transport in the Chamonix Valley operates under extreme geographic and demographic pressures. During July and August, the population density of the valley expands exponentially as alpinists, trail runners, and sightseers converge on the Mont Blanc massif. The valley floor constitutes a narrow gorge with a single primary road artery, the D1506, running from Les Houches through to Vallorcine. This topological restriction creates severe bottlenecks when traffic volume spikes.

Attempting to navigate this infrastructure using a personal or rental vehicle is a critical logistical error. The route acts as a major international freight corridor connecting France and Italy via the Mont Blanc Tunnel. Local traffic inevitably mixes with heavy goods vehicles, resulting in daily gridlock. Resorting to private cars for short journeys between valley towns guarantees wasted time in stationary traffic and extreme difficulty in securing parking at highly congested lift stations like the Aiguille du Midi or Brévent.

Efficiently getting around Chamonix in summer demands a strict reliance on the established multimodal transit network. The local municipality has heavily engineered the Chamonix valley public transport system to process high passenger volumes rapidly. Success requires abandoning the standard reliance on a personal vehicle and adopting a structured approach that integrates pre-booked point-to-point transfers with the local high-frequency bus and rail networks. This methodology is the only viable path to executing a tight alpine itinerary.

Shifting to a Car-Free Valley Infrastructure

The local government enforces stringent environmental protocols to combat glacial retreat and preserve alpine air quality. By 2026, the push towards a car-free Chamonix logistics model is heavily subsidized and systematically enforced. The municipality heavily restricts central parking zones and implements strict emissions regulations during peak summer heatwaves, actively penalising personal car usage within the resort boundaries.

To facilitate this transition, the valley operates the Carte d’Hôte (Guest Card) system. This document is issued by official accommodation providers upon arrival and grants free or heavily discounted access to the local bus and train networks spanning the length of the valley. Utilizing this card eliminates individual transit costs and integrates the user into the primary movement flow. Riders simply present the digital or physical card upon boarding, removing friction at transit hubs.

Integrating this local network requires isolating the long-haul transit from daily micro-mobility. The optimal strategy utilizes dedicated transport to breach the valley boundary, depositing travelers and their heavy equipment directly at their base camp. Once established in the resort, visitors must pivot entirely to the Carte d’Hôte infrastructure. This bifurcated approach secures the reliability of professional transport for the critical arrival phase while leveraging subsidized local networks for daily trail access.

Geneva Airport Arrival and Initial Transit Execution

Terminal Operations and Baggage Retrieval at GVA

Geneva Airport (GVA) functions as the mandatory ingress point for international arrivals heading to the Haute-Savoie region. Peak summer weekends generate passenger volumes mirroring the height of the winter ski season. The composition of baggage shifts heavily towards cumbersome sporting equipment, including rigid bike boxes, extensive climbing hardware, and heavy camping loads. Navigating the arrivals hall under these conditions requires immediate execution of pre-planned logistics.

The extraction process begins at the baggage carousels. Standard luggage is processed through the main system, but oversized sporting goods are diverted to dedicated oversized baggage counters, typically located at the far end of the Swiss sector terminal. Passengers must divide their group if necessary, simultaneously monitoring standard belts and the oversized drop zone to prevent delays. Ground crew handling of heavy gear is manual, routinely resulting in processing times that exceed standard luggage delivery.

Transitioning from the terminal to the transport staging area is a high-friction event. Relying on public train connections from GVA requires navigating the heavy bags through the airport concourse, boarding a Swiss rail service to Geneva Cornavin, and executing multiple regional train or bus transfers before reaching the French border. This public route introduces numerous failure points, severe physical fatigue, and massive time deficits before the alpine itinerary has even begun.

Executing the Direct Route via Autoroute Blanche

The only mathematically efficient method for breaching the valley is a pre-booked, direct Geneva to Chamonix transfer. This protocol entirely bypasses the public transit queues and multi-stage connections. Professional drivers monitor flight telemetry, adjusting arrival windows to account for airspace delays. Upon exiting customs, passengers are immediately intercepted and routed directly to the loading zone, eliminating terminal loitering and route-finding confusion.

Vehicle allocation is critical when transporting bikes to Chamonix or moving heavy mountaineering gear. Ad-hoc terminal taxi ranks operate standard sedans and compact vans incapable of accommodating multi-person alpine expeditions. Booking an Alps2Alps transfer guarantees the deployment of a long-wheelbase vehicle specifically configured for oversized cargo. This structural capacity ensures equipment is transported securely inside the cabin without requiring external racks or compromising passenger seating space.

The route execution utilizes the Autoroute Blanche (A40), prioritizing velocity and direct access. The 80-kilometer transit typically requires 75 to 90 minutes under standard summer conditions. Drivers bypass local traffic traps, executing a direct kerbside drop-off at the specified accommodation in Chamonix. This point-to-point delivery model neutralizes the logistical burden of moving heavy equipment through steep, pedestrianized alpine streets, allowing immediate progression to equipment preparation and acclimatization.

Alps2Alps Geneva to Chamonix Transfer Logistics

Fleet Architecture and Cargo Capabilities

Securing an Alps2Alps transfer dictates the deployment of highly specific vehicle architecture designed for alpine logistics. The fleet consists predominantly of long-wheelbase, high-capacity passenger vans. This structural configuration is a strict requirement for summer operations, where passenger manifests routinely include oversized technical equipment such as rigid mountain bike boxes, bouldering crash pads, and massive mountaineering expedition packs. Standard saloon vehicles and compact taxis lack the internal cubic capacity to process these loads without breaching safety regulations.

Executing successful terminal extraction requires precise cargo declaration during the initial digital booking phase. Passengers must quantify the exact dimensions and volume of their technical gear. Failing to register a 32kg downhill bike box results in the dispatch of a standard-capacity vehicle, triggering an immediate logistical failure at the airport terminal. Accurate data entry ensures the allocated van features the necessary rear cargo bay dimensions to transport all equipment internally.

Internal cargo transport is a non-negotiable protocol for high-value alpine equipment. Alps2Alps drivers load heavily padded bike bags and technical climbing hardware vertically inside the reinforced cargo zone. External roof racks or rear-mounted tow-ball carriers are strictly avoided to eliminate the risk of weather contamination, road debris impact, or opportunistic theft during brief transit stops. This internal loading methodology guarantees equipment integrity from the Geneva tarmac to the final alpine destination.

Route Optimisation and Door-to-Door Execution

The standard trajectory for a Geneva to Chamonix transfer relies on the A40 Autoroute Blanche. This primary arterial route bypasses the convoluted secondary road networks, delivering a highly efficient 80-kilometre transit. Under standard summer operational conditions, professional drivers execute this corridor in 75 to 90 minutes. This velocity drastically outperforms all public rail or bus alternatives, which are heavily compromised by mandatory connection layovers and indirect routing.

Approaching the Chamonix Valley introduces severe traffic bottlenecks, particularly where the autoroute constricts into the D1506 near Les Houches. Alps2Alps drivers utilize real-time GPS telemetry and extensive local topographical knowledge to navigate peak summer gridlock. When the main valley floor arteries fail due to heavy tourist influx, drivers redirect through secondary residential access roads to maintain forward momentum and adhere to strict schedule parameters.

The transfer sequence concludes with a strict door-to-door delivery protocol. The vehicle terminates the route directly at the designated accommodation within Chamonix or its peripheral villages like Argentière or Les Houches. Drivers execute a kerbside offload, entirely neutralizing the physical burden of transporting heavy, cumbersome equipment through crowded pedestrian zones or up steep alpine gradients. This immediate deposit allows teams to commence gear assembly and acclimatization without secondary transit delays.

Valley Mobility: Navigating the 2026 Summer Bus Network

The Chamonix Mobilité Infrastructure and Carte d’Hôte

The 2026 Chamonix valley public transport system, operated under the Chamonix Mobilité banner, functions as the primary mechanism for daily intra-valley transit. The network consists of a high-frequency fleet, increasingly dominated by electric and low-emission articulated buses. This infrastructure processes thousands of hikers, climbers, and sightseers daily, completely rendering personal rental vehicles obsolete for navigating the 20-kilometre stretch from Les Houches to Vallorcine.

Access to this network is governed entirely by the Carte d’Hôte (Guest Card) protocol. Official accommodation providers—hotels, registered chalets, and official campsites—issue this document upon arrival. Presentation of a valid physical or digital Carte d’Hôte grants complimentary, unrestricted access to the urban bus network. Attempting to navigate the valley without securing this specific credential forces reliance on individual point-to-point ticket purchases, severely inflating the daily operational budget.

Route mapping relies on two primary arteries: Line 1 and Line 2. These routes run the entire length of the valley floor, connecting all major lift stations, railway depots, and town centres. During the peak operational months of July and August, frequency parameters dictate a bus arrival every 15 to 20 minutes. Early morning services commence before 06:00 to accommodate alpinists targeting high-altitude objectives, while late evening sweeps extract hikers from peripheral villages post-sunset.

Equipment Integration and Boarding Protocols

Boarding standard public transit with highly specialized alpine equipment necessitates strict procedural adherence. Standard Line 1 and Line 2 buses operate at maximum passenger capacity during peak morning and late afternoon windows. Passengers carrying ice axes, crampons attached to external pack loops, and heavily loaded 60-litre expedition bags must remove their packs and secure sharp implements prior to boarding to prevent injury to surrounding passengers and expedite the loading sequence.

Transporting mountain bikes via the local bus network utilizes the dedicated VéloBus system. Standard passenger buses explicitly prohibit the loading of full-suspension downhill or enduro bicycles. To bypass this restriction, the municipality deploys specific vehicles equipped with reinforced rear-mounted racks or modified internal cargo zones. Riders must identify these designated services on the digital timetable; attempting to force a bicycle onto a standard commuter service results in immediate denial of boarding by the operator.

Strategic deployment of the bus network optimizes lift access and eliminates parking friction. Driving a personal vehicle to the Les Praz base station for the La Flégère cable car guarantees failure; the paid parking infrastructure reaches capacity by 08:30 in mid-summer. Utilizing the bus network bypasses this bottleneck entirely. The transport drops passengers precisely at the lift terminal entrance, allowing immediate progression to the ticket barriers and maximizing time spent in the high alpine zones.

Rail Infrastructure: Utilising the Mont Blanc Express

Operational Scope and Free-Transit Parameters

The Mont Blanc Express operates as the secondary transport spine of the Chamonix Valley. This metre-gauge railway connects Le Fayet in France to Martigny in Switzerland, slicing directly through the valley floor. Its primary utility lies in its complete isolation from the D1506 road network, rendering it immune to the severe vehicular gridlock that paralyses the region during peak July and August transit windows.

Financial efficiency relies on strict Carte d’Hôte integration. The physical or digital guest card activates a localised free-transit zone bounded exclusively between the Servoz and Vallorcine stations. Commuting beyond these demarcations—descending to Saint-Gervais or crossing the Swiss border towards Finhaut or Martigny—mandates the purchase of supplemental cross-border rail tickets. Operating outside the free zone without correct ticketing incurs immediate, unnegotiable fines from onboard conductors.

Timetable execution during the 2026 summer season demands precise schedule adherence. Trains operate on high-frequency rotations, arriving at 30-minute intervals during peak morning and late afternoon windows. Alpinists targeting the Aiguilles Rouges or the Argentière glacier utilise the earliest available departures to secure optimal climbing conditions. Missing a targeted departure truncates the operational day and compromises high-altitude weather windows.

Technical Equipment and Bicycle Transport Directives

Boarding the Mont Blanc Express with technical alpine equipment requires strict spatial management. The carriages feature specific configurations prioritising seating density over bulk storage. Alpinists must collapse trekking poles, sheath ice axes, and remove 60-litre expedition packs prior to boarding. Depositing unrestrained hardware in aisles blocks transit corridors and violates operational safety protocols.

Transporting mountain bikes on this rail infrastructure during peak summer is heavily restricted. The regional transit authority implements severe blackout windows throughout July and August, explicitly prohibiting bicycles aboard the Mont Blanc Express during peak commuter hours to maximise human passenger capacity. Riders attempting to board with downhill or enduro rigs during these restricted blocks face immediate denial of entry by station personnel.

Strategic utilisation of the railway optimises linear route execution. Trail runners and hikers execute high-mileage traverses, such as the Grand Balcon Sud or sections of the Tour du Mont Blanc, without the necessity of returning to a central parking location. Depositing a team at the Les Houches terminal and extracting them via the Vallorcine station 20 kilometres away maximises forward progression and eliminates inefficient loop tracking.

Uplift Protocols: Maximising Chamonix Summer Lift Passes

The Mont Blanc MultiPass Architecture

The Mont Blanc MultiPass constitutes the absolute baseline for executing a high-volume alpine itinerary. This unified lift ticket grants unrestricted access to the entire high-altitude mechanical infrastructure, including the Aiguille du Midi cable car, the Montenvers Mer de Glace train, the Tramway du Mont Blanc, and the primary gondolas across Brévent, Flégère, Grands Montets, and Balme. Purchasing isolated, single-ascent tickets for these facilities is mathematically inefficient and rapidly exhausts standard travel budgets.

Selecting the correct duration parameters dictates cost optimisation. Operators offer consecutive and non-consecutive day structures. The 2026 pricing model penalises consecutive passes if weather systems force rest days. Procuring a non-consecutive format, such as 4 days within a 6-day window, allows users to ground themselves during electrical storms or high-wind events without burning active pass capital.

Digital procurement bypasses severe infrastructural bottlenecks. Physical ticket offices at the Aiguille du Midi and Montenvers base stations generate multi-hour queues during peak July mornings. Users must acquire the hands-free RFID smartcard online prior to arrival or via automated central kiosks in Chamonix. This hardware permits immediate progression to the boarding turnstiles, preserving critical morning hours for high-alpine deployment.

Mandatory Reservation Systems and Crowd Mitigation

Accessing the Aiguille du Midi dictates strict adherence to a mandatory digital reservation system. Possession of a valid MultiPass does not guarantee boarding rights. Users must log into the operator’s portal days in advance to secure a specific, timestamped boarding cabin. Arriving at the base station without this pre-booked time slot results in a definitive denial of uplift, stranding the individual on the valley floor regardless of ticket status.

Similar reservation protocols govern the Tramway du Mont Blanc and the Montenvers railway. These rack-and-pinion train networks possess finite seating capacities that cannot scale to match peak summer tourist influx. Users targeting the Mer de Glace or the Nid d’Aigle must bind their MultiPass to a designated departure train. Missing the allocated boarding sequence forces the user to the back of the standby queue, frequently resulting in hours of static delay.

High-altitude infrastructure demonstrates extreme sensitivity to meteorological variance. High winds routinely force the immediate shutdown of the Aiguille du Midi upper section, while electrical storms ground the Brévent and Flégère gondolas. The core strategic advantage of the MultiPass is rapid pivot capability. When the 3,800-metre zones close, users immediately redirect to lower, weather-shielded sectors like the Les Houches tree-line trails without incurring secondary ticketing costs.

Car-Free Navigation and Pedestrian Mobility Strategies

Designing a High-Efficiency Pedestrian Itinerary

The geographical layout of the Chamonix town centre dictates a strictly pedestrian approach during peak summer operations. The municipality enforces extensive pedestrianised zones (Zones Piétonnes), primarily mapping across the Rue du Docteur Paccard and the Rue des Moulins. Operating a personal or rental vehicle within these sectors is physically blocked by hydraulic bollards and monitored by automated camera systems that issue immediate, unappealable fines to unauthorised license plates.

Navigating these zones requires strategic base camp selection. Visitors must secure accommodation within a 500-metre radius of the central transport hubs, specifically targeting the Chamonix Sud bus interchange or the main SNCF railway station. This proximity parameter eliminates the necessity for secondary micro-transit when carrying heavy technical day packs or returning in a state of physical depletion from high-altitude ascents on the Mont Blanc massif.

Walking infrastructure extends beyond the urban core via the Promenade de l’Arve. This dedicated pedestrian and cycle corridor connects Les Praz directly to Les Bossons, completely isolated from the congested D1506 highway. Utilising this route enables rapid, safe transit between the central town and peripheral lift stations, such as the Flégère cable car base, bypassing vehicular traffic and nullifying the requirement for local bus network integration for short-range movements.

E-Bike Integration and Micro-Mobility Networks

Electric micro-mobility replaces the rental car for targeted intra-valley transit. The 2026 local infrastructure heavily subsidises e-bike adoption, installing high-capacity charging arrays at major lift terminals, municipal buildings, and central town squares. Riders deploying e-bikes bypass the chronic parking shortages that paralyse high-traffic zones like the Aiguille du Midi base station or the Montenvers train depot during the July and August peak.

The local municipal bike-sharing ecosystem, running parallel to private rental hubs, supplies on-demand access to pedal-assist hardware. Procuring an e-bike permits users to execute the 8-kilometre transit from the Chamonix centre to the Argentière base station in under 30 minutes. This transit mode operates entirely independent of the public bus network’s timetable constraints, granting absolute schedule control to the user.

Strict operational parameters govern e-bike deployment. Cyclists must remain on designated shared paths and are strictly prohibited from riding through highly congested central pedestrian streets during peak daylight hours. Violation of these spatial restrictions triggers immediate interdiction by municipal police units. Furthermore, deploying secure, heavy-duty locking mechanisms is a non-negotiable requirement; high-value e-bikes constitute primary targets for organised theft rings operating across the regional borders.

Specialist Equipment Transit: Bicycles and Alpine Gear

Aviation and Ground Transfer Logistics for Heavy Loads

Transporting technical alpine gear and downhill mountain bikes demands precise load engineering prior to terminal arrival. Airlines enforce rigid weight and dimensional restrictions, typically capping oversized sporting equipment at 32kg. Downhill bikes, bouldering crash pads, and extensive trad climbing racks routinely breach these thresholds. Users must extract dense hardware—such as pedals, tools, and carabiners—and distribute them into standard hold luggage to guarantee the primary equipment container passes terminal weigh-ins without incurring exorbitant overage fees.

The critical failure point in equipment transit occurs at the airport-to-resort transition. Standard taxi ranks at Geneva Airport lack the internal cubic volume to process multiple rigid bike boxes or expedition-scale duffel bags. Passengers must secure a high-capacity Geneva to Chamonix transfer well in advance to guarantee the allocation of a long-wheelbase vehicle. This architectural specification ensures all cargo is secured internally, mitigating the structural risks and weather exposure associated with external roof mounting. Alps2Alps transfer protocols mandate the explicit declaration of all oversized cargo during the initial digital booking sequence. Failure to register specific dimensions and item counts results in the deployment of a standard-capacity passenger van, forcing the driver to reject the load at the GVA arrivals terminal. Accurate volume data guarantees direct, point-to-point delivery to the specified accommodation in Chamonix without triggering secondary handling delays or requiring supplementary transport vehicles.

Local Transit Restrictions for Technical Equipment

The Chamonix valley public transport network imposes severe restrictions on the movement of specialist equipment during the peak summer operational window. Standard commuter buses and the Mont Blanc Express strictly prohibit fully assembled mountain bikes during high-volume passenger hours. Cyclists relying on public transit must identify and utilise the designated VéloBus services, which operate on highly restricted schedules and feature finite external rack capacities that fill rapidly during morning ascents.

Alpinists face strict boarding protocols when transporting technical hardware on local networks. Ice axes, crampons, and ski mountaineering gear must be fully sheathed or stored internally within protective, puncture-resistant transport bags. Conductors and bus drivers exercise absolute authority to deny boarding to individuals displaying exposed sharp implements or carrying unsecured 60-litre expedition packs that obstruct primary transit corridors or threaten the physical safety of dense passenger loads.

Moving heavy equipment via the high-altitude mechanical lift network requires total compliance with operator-specific cargo regulations. The Aiguille du Midi cable car and the Montenvers train severely restrict the volume of baggage permitted per individual passenger. Paragliders must present canopies packed to specific volume limits. Large-scale expedition hauling bags are routinely relegated to secondary, cargo-only lift ascents, forcing climbing teams to separate from their primary logistical supplies during the initial uplift phase and delay base camp construction.

Chamonix Summer Transport & Travel Logistics FAQ 2026

1. How to get around Chamonix in summer?
Secure the Carte d’Hôte from your official accommodation provider upon arrival. Deploy this digital or physical card for unrestricted access to the Chamonix Mobilité bus network and the Mont Blanc Express rail line operating strictly between Servoz and Vallorcine[1]. Utilise pre-booked point-to-point transfers for airport transit and municipal e-bikes for high-efficiency, short-range movement within the central pedestrian zones.

2. Is it worth going to Chamonix in summer?
Yes. The infrastructure fully supports high-volume alpine tourism from June to September. The valley provides unparalleled access to world-class alpinism, technical trail running, and high-altitude hiking networks, including sectors of the Tour du Mont Blanc. The mechanical lift systems operate at peak capacity to facilitate rapid deployment to the 3,800-metre zones.

3. How crowded is Chamonix in July?
July represents peak operational density. Expect severe demographic and vehicular bottlenecks. The primary D1506 highway experiences daily gridlock. Access to critical infrastructure, such as the Aiguille du Midi cable car or the Montenvers Mer de Glace train, requires mandatory digital reservations days in advance. Walk-up access to major attractions is effectively non-existent.

4. Is Chamonix expensive in the summer?
Yes. Expect peak-season tariffs across all sectors. A standard UK traveller must allocate €100–€150 per day for mid-range meals, lift passes, and incidentals, excluding base accommodation costs. Single-ascent tickets for primary lifts like the Aiguille du Midi exceed €80. Mitigate expenditure by relying entirely on the free Carte d’Hôte transit network and purchasing multi-day, non-consecutive lift passes.

5. How long to spend in Chamonix in summer?
Allocate a minimum of five to seven days. The Haute-Savoie microclimate features volatile summer weather patterns, including severe afternoon thunderstorms that force immediate lift closures and route aborts. A tight two-day itinerary mathematically guarantees failure if a low-pressure system grounds the mechanical infrastructure. A five-day window ensures sufficient flexibility to execute high-altitude objectives safely.

6. How hot is Chamonix in July?
Valley floor temperatures consistently reach 24°C to 30°C, with historical heatwave spikes exceeding 35°C. However, the thermal gradient dictates a rapid drop at altitude. While the valley requires standard summer cooling protocols, temperatures at the 3,842-metre Aiguille du Midi summit routinely sit near freezing, exacerbated by high-velocity alpine wind chill.

7. What part of Chamonix to stay in during summer?
Base selection dictates logistical efficiency. For maximum transport integration, secure accommodation in Chamonix Centre or Chamonix Sud. This proximity eliminates secondary transit to the primary bus interchanges and the SNCF railway station. To avoid peak urban congestion while maintaining lift access, target peripheral zones like Les Praz or Argentière, provided they sit within a 500-metre radius of a Mont Blanc Express rail depot.

8. What to wear in Chamonix in July?
Implement a strict microclimate layering system. Valley operations require lightweight, highly breathable summer apparel. Ascending above 2,500 metres mandates immediate access to insulated mid-layers, windproof shells, and UV-blocking eyewear. Operating in high alpine zones with only valley-appropriate mesh clothing guarantees rapid thermal depletion and exposure during unexpected mechanical delays.

9. What to do around Chamonix in summer?
Execute high-altitude ascents via the Aiguille du Midi and Skyway Monte Bianco. Navigate the Mer de Glace via the Montenvers train. Deploy to the Brévent or Flégère sectors for lift-accessed hiking toward Lac Blanc. Utilise the designated mountain biking tracks in the Le Tour and Les Houches sectors, or execute technical alpine climbing routes across the Mont Blanc massif.

10. What is the hottest month in Chamonix?
July holds the statistical peak for temperature in the Chamonix Valley, followed closely by August. This timeframe generates maximum thermal convection, resulting in high baseline temperatures at the valley floor and triggering predictable, severe afternoon thunderstorms across the mountain ranges. Avoid peak afternoon ascents during this period.