Cycling weather in the French Alps
The French Alps are legendary in cycling — Alpe d'Huez, Col du Galibier, Col de l'Iseran. But legendary climbs come with demanding weather: rapid afternoon storms, strong summit winds and sharp temperature gradients between valley and high pass. Get a forecast for your actual route, not the nearest town.
See wind, rain and temperature along every kilometre of your route — not just at the start.
Why a city forecast isn't enough
A forecast for Grenoble or Bourg-Saint-Maurice tells you little about conditions on the Galibier. The French Alps sit between Atlantic and Mediterranean weather patterns, creating fast-changing conditions above 2000 m. RouteWeather maps the forecast to your GPS line so you can plan every transition.
What changes along a long route
- Wind speed and direction change across passes and valleys
- Temperature drops ~6–7 °C per 1000 m of elevation gain
- Rain and storm timing differs from city to mountain
- Your start time determines whether you ride into headwind or tailwind
- Weather windows shift depending on how long your ride takes
See it in action
Try example route in the French AlpsFrequently asked questions
What is the best time to cycle the classic French Alpine cols?
High passes like Iseran and Galibier are typically snow-free from June to early October. July has long daylight hours but brings afternoon thunderstorms. Early morning starts are strongly recommended on major passes. Use RouteWeather to check hourly forecasts for your exact start time.
How do afternoon storms affect climbing in the French Alps?
Thunderstorms can develop quickly above 2000 m from early afternoon, especially in July and August. A pass that is clear and sunny at 9 am can have lightning and hail by 2 pm. Checking the hourly weather forecast for the summit of your climb is essential safety planning.
Does weather change along a long route?
Dramatically. Valley starts are typically warmer and calmer; conditions deteriorate rapidly as you gain elevation. A route-based forecast shows you each transition by kilometre so you can plan layers and turnaround points.