Your route forecast
Conditions on the route, over the cols & ahead
Hazards & advisories
Measured on the ground
High point, hour by hour
Temperature is lapse-rate corrected to the true altitude. "Feels" is wind chill using the free-air wind at that height, not the sheltered-valley 10 m wind. ⚡ marks thunderstorm hours.
Snow & avalanche
Rain, rockfall & landslide risk
Getting there
Best days to walk
Each day is scored on its own windows: cols/high point 07:00–14:00, trail 07:00–18:00, views 06:00–10:00. Official warnings cap the hours they cover; reported closures cap the next 3 days; later days show the weather outlook.
Do the models agree?
Conditions for your dates
Uses the typical itinerary (3–4 days). Stages beyond the 7-day forecast show as "not yet forecast" — check back as your date approaches.
Route & freezing level
Where the risk is
Overnight altitudes
Warnings & avalanche bulletins
Latest news & closures
Social & official channels
X, Facebook and Instagram offer no public feed we can read reliably, so these are linked rather than scraped. Treat group posts as unverified until confirmed by Météo-France, the préfecture, the park or the news sources above.
GR91 — Traversée des Hauts-Plateaux du Vercors
The wildest part of the GR91: from Corrençon-en-Vercors across the Hauts-Plateaux nature reserve — the largest in mainland France — by the Cabane de Carrette, the Darbounouse meadows and the Jasse du Play, down to Châtillon-en-Diois. There are only basic unstaffed cabins. Weather risk is fog on the featureless karst plateau (navigation), storms, and heat; the plateau is snow-covered in winter.
Help on the trail
Bookings & rules
No permit is needed to walk these routes. Rules for bivouac, dogs and fires differ between parks and change — confirm with the park or refuge before you go.
How the score works
A route is not a point. We pull an hourly forecast for every waypoint (5 on this route), corrected to its real altitude — MET Norway's Locationforecast (ECMWF-based) — plus the past days of rain kept from earlier forecasts and corrected with Météo-France rain gauges. Gusts at the high point, storm energy and the 0 °C level come from Open-Meteo when available; otherwise gusts are estimated from wind speed.
High point — wind at col height (free-air wind at that altitude), wind chill, snowfall, cloud and thunderstorms during the 07:00–14:00 crossing window. Gust bands follow the Beaufort scale (gale force, 62 km/h, impedes walking).
Snow & avalanche — fresh-snow load, new snow depth and time since snowfall give a path status. Where Météo-France (BRA, November–June) or the Swiss SLF publishes an avalanche bulletin, the official danger level is used; otherwise the level shown is a model estimate and is labelled as such.
Rain & slopes — rolling 3–96 h rainfall at each steep section against the European landslide rainfall thresholds of Guzzetti et al. (2007), corrected with Météo-France rain gauges and boosted by rain/flood warnings; the hazard fades once rain stops.
Official warnings — Météo-France Vigilance (and Meteoalarm for the Italian and Swiss stages): orange and red cap the score for the hours they cover; Vigicrues flood vigilance on nearby rivers too.
Reports — French regional press and Google News are classified by relevance, severity and source trust. A credible closure caps the score; a later reopening clears it. Community posts never move the score.
Not an official forecast. Always follow Météo-France warnings and avalanche bulletins, préfecture and park notices, refuge guardians and mountain rescue advice. In an emergency call 112.
Weather forecast from MET Norway (CC BY 4.0). Data: Open-Meteo (gusts & model comparison), Météo-France Vigilance & avalanche bulletins, SLF, Meteoalarm, Hub'eau, Vigicrues, French regional news. All France routes · CoastMetric UK