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Grenoble sits in a flat valley at 214m (702ft) elevation, surrounded by the Chartreuse, Vercors, and Belledonne mountain ranges. This geography creates a semi-continental climate with four distinct seasons: cold, sometimes snowy winters, warm summers with afternoon thunderstorms, and short, pleasant spring and autumn transitions. The city averages 935mm of rain per year spread across 106 rainy days. Unlike the French Riviera, Grenoble gets real winter with 20-30 snow days annually, though the valley floor sees less accumulation than the surrounding ski resorts at 1,500m+. For more details, see our things to do guide.
Temperatures range from average January lows of -1°C (30°F) to July highs of 27°C (81°F). Heatwaves can push summer temperatures past 35°C (95°F), while cold snaps bring valley temperatures down to -10°C (14°F). The surrounding mountains create a “bowl effect” that can trap warm air in summer and cold air in winter, with frequent temperature inversions where valley mornings are colder than mountain afternoons. For more details, see our events and festivals guide.
Grenoble Weather by Month
| Month | Avg High | Avg Low | Rain (mm) | Rain Days | Sun (hrs) |
|---|---|---|---|---|---|
| Jan | 6°C / 43°F | -1°C / 30°F | 63 | 9 | 95 |
| Feb | 8°C / 46°F | 0°C / 32°F | 58 | 8 | 115 |
| Mar | 13°C / 55°F | 3°C / 37°F | 63 | 9 | 170 |
| Apr | 16°C / 61°F | 6°C / 43°F | 68 | 9 | 185 |
| May | 21°C / 70°F | 10°C / 50°F | 79 | 10 | 215 |
| Jun | 25°C / 77°F | 13°C / 55°F | 72 | 8 | 250 |
| Jul | 27°C / 81°F | 15°C / 59°F | 58 | 7 | 285 |
| Aug | 27°C / 81°F | 15°C / 59°F | 66 | 8 | 255 |
| Sep | 23°C / 73°F | 12°C / 54°F | 83 | 8 | 200 |
| Oct | 17°C / 63°F | 8°C / 46°F | 92 | 10 | 145 |
| Nov | 10°C / 50°F | 3°C / 37°F | 80 | 10 | 90 |
| Dec | 6°C / 43°F | 0°C / 32°F | 67 | 9 | 80 |
Winter (December to February)
Winter in Grenoble means cold mornings and cool afternoons. December and January average just 2-6°C (36-43°F) with nighttime temperatures dipping below freezing on 15-20 days per month. Snow falls in the valley 6-8 days per month, though accumulation rarely exceeds 5cm on the valley floor. The ski resorts of Chamrousse (30km away) and Les 7 Laux (35km) receive 2-3m of snow at 1,500m+. December is the darkest month with only 80 hours of sunshine, while February improves to 115 hours. For more details, see our neighborhoods guide.
Spring (March to May)
March starts cool at 13°C (55°F) but warms to a pleasant 21°C (70°F) by May. This is a transitional season with variable conditions: you may get sunny 20°C days in March followed by a late snow flurry. April and May bring the year’s first thunderstorms, typically in the late afternoon after warm mornings. May opens the terrace season at Place Grenette in the old town, with 215 hours of sunshine and extended daylight. Spring rain totals are moderate at 63-79mm per month. For more details, see our where to stay guide.
Summer (June to August)
Summer is warm with July and August both averaging 27°C (81°F) highs and 15°C (59°F) lows. Heatwaves push temperatures above 35°C (95°F) for 5-10 days per summer, most often in late July. The valley traps heat, making Grenoble feel hotter than the official temperature suggests. Afternoon thunderstorms are common, especially in June (8 rain days), as moist air rises against the surrounding peaks. July is the driest month at 58mm of rain across just 7 days. With 285 hours of July sunshine, it’s the best month for outdoor activities like hiking in the Chartreuse or cycling the Isère river paths. For more details, see our travel tips guide.
Autumn (September to November)
September holds summer warmth at 23°C (73°F) but brings the year’s highest rainfall at 83mm as Atlantic fronts return. October cools quickly to 17°C (63°F) with the most rainy days (10) of any month at 92mm. The surrounding forests turn gold and red, making it a prime season for hiking in the Vercors and Chartreuse. November drops to 10°C (50°F) with foggy mornings that can last until midday in the valley. By late November, the first snow dusts the Belledonne peaks visible from the city.
For seasonal recommendations on when to visit, see our best time to visit Grenoble guide which covers festivals, crowd levels, and the ideal windows for skiing and hiking.
Mountain vs. Valley Weather
The temperature difference between Grenoble at 214m and Chamrousse at 1,650m averages 8-10°C (14-18°F) year-round. It can be raining in the city while snow falls 500m above. The foehn wind (locally called “vent du sud”) occasionally blows warm, dry air over the Alps, raising valley temperatures by 5-8°C in a few hours. For real-time weather, check the Bastille webcam which shows the Isère valley and Belledonne range.
