Few mainland French towns have colder winter nights than Grignon
Sunny July days climb to about 27.5°C. Of all months, December brings the most rain and April the least. It is a wet place: more rain falls here than on 98% of mainland French towns. Keep the boiler serviced for the months from November to March, which average under 10°C.
These are the figures of Météo-France’s Gilly-sur-Isère station, 2.3 km west.
A year in Grignon at a glance
Each month’s typical high and low in °C, at the Gilly-sur-Isère station.
What a year in Grignon feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Gilly-sur-Isère.
About 1,354 mm of rain a year
December is the wettest month and April the driest. About 49 days a year bring 10 mm or more. 2nd wettest of 37 towns of 2,500+ in Savoie.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Bourg-Saint-Maurice
A frosty town: 94 frosts and 85 days of 25°C a year
On about 94 nights a year the air drops to 0°C or below, and on about 4 days it stays below freezing all day. About 85 days a year reach 25°C, and 26 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Gilly-sur-Isère: a frost is a night of 0°C or below, a summer day (jour d’été) 25°C or more, a hot day (forte chaleur) 30°C or more.
The Météo-France station at Gilly-sur-Isère
Gilly-sur-Isère is 2.3 km west of Grignon. Every figure on this page is the station’s, not a measurement in Grignon itself.
| Station (Météo-France number) | Gilly-sur-Isère (73124001) |
| Distance from the town | 2.3 km west |
| Station altitude | 330 m |
| Town altitude (its center) | 327 m |
| Period | 1991–2020 |
| Sunshine measured at | Bourg-Saint-Maurice, 31 km away |
TownRatings matches each commune to one station with at least 24 years of temperature and rain records: the nearest, counting every 100 m of height difference as 10 km, never across the sea.
How Grignon compares
Against the 4,385 towns of 2,500 or more in mainland France, each read from its own matched station. The dots are the other towns of 2,500+ in Savoie.
Nearby towns’ climate
The nearest towns of 2,500+ within 29 km. Where a neighbor uses the same station its figures are the same: the differences you’d feel over a few kilometers aren’t in the normals.
| Town | Station | July high | January low | Rain a year |
|---|---|---|---|---|
| Grignon | Gilly-sur-Isère | 27.5°C | −2.8°C | 1,354 mm |
| Gilly-sur-Isère 2 km | same station | 27.5°C about the same | −2.8°C about the same | 1,354 mm |
| Albertville 2.6 km | same station | 27.5°C about the same | −2.8°C about the same | 1,354 mm |
| Mercury 3.7 km | same station | 27.5°C about the same | −2.8°C about the same | 1,354 mm |
| Ugine 12 km | Ugine | 26.4°C 1.1°C cooler | −0.8°C 2°C milder | 1,399 mm |
| Faverges-Seythenex 13 km | Ugine | 26.4°C 1.1°C cooler | −0.8°C 2°C milder | 1,399 mm |
| La Léchère 15 km | Moûtiers | 28.4°C 0.9°C warmer | −1.9°C 0.9°C milder | 930 mm |
Grignon weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Gilly-sur-Isère station; sunshine at Bourg-Saint-Maurice.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.3°C | −2.8°C | 1.7°C | 136 mm | 110 |
| February | 8.8°C | −2.1°C | 3.3°C | 106 mm | 122 |
| March | 14.1°C | 1.5°C | 7.8°C | 108 mm | 170 |
| April | 18.0°C | 4.5°C | 11.3°C | 93 mm | 176 |
| May | 21.8°C | 8.7°C | 15.3°C | 109 mm | 200 |
| June | 25.4°C | 12.3°C | 18.9°C | 105 mm | 226 |
| July | 27.5°C | 14.0°C | 20.7°C | 100 mm | 249 |
| August | 27.1°C | 13.8°C | 20.5°C | 108 mm | 232 |
| September | 22.7°C | 10.2°C | 16.4°C | 97 mm | 189 |
| October | 17.7°C | 6.2°C | 12.0°C | 109 mm | 143 |
| November | 10.9°C | 1.2°C | 6.1°C | 126 mm | 99 |
| December | 6.5°C | −1.9°C | 2.3°C | 158 mm | 94 |
| Year | 17.2°C | 5.5°C | 11.4°C | 1,354 mm | 2,009 |
Where Grignon’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Gilly-sur-Isère, 2.3 km away: statistics for 1991–2020.
- Which station: among stations with at least 24 of the 30 years of temperature and rain, the nearest to the commune’s population-weighted center, counting each 100 m of height difference as 10 km; mainland towns use mainland stations and each overseas département its own.
- Altitudes: the town’s from IGN’s RGE ALTI® at its population-weighted center; the station’s from Météo-France.
- Sunshine: the nearest station with at least 10 years of sunshine records, Bourg-Saint-Maurice, 31 km away.
- Comparisons: every town of 2,500 or more in mainland France, read the same way; the dots are the towns of 2,500+ in Savoie.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Grignon’s climate
How warm does Grignon get in summer?
July is the warmest month, with average highs of 27.5°C. About 85 days a year reach 25°C, more than 77% of mainland French towns, and about 26 reach 30°C.
How cold does Grignon get in winter?
January nights average −2.8°C. The air drops to 0°C or below on about 94 nights a year, and about 4 days a year stay below freezing all day.
How much rain does Grignon get?
About 1,354 mm a year, more than 98% of mainland French towns. December is the wettest month (158 mm) and April the driest (93 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Bourg-Saint-Maurice (31 km away), averages 2,009 hours of sunshine a year.
Are these figures for Grignon itself?
No: they are the normals of the Météo-France station matched to Grignon, Gilly-sur-Isère, 2.3 km away. France publishes its climate normals by station, not by commune; a valley, a hill or the sea can make a difference over a few kilometers.
Where do these figures come from?
Météo-France’s fiches climatologiques: 30-year averages (1991–2020) for each of its long-running stations, published as open data since 2024. They are normals, not a forecast.
Source: Météo-France, fiches climatologiques, 1991–2020 statistics (station GILLY SUR ISERE, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Grignon →
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.