Saint-Cassien has colder winter nights than 92% of mainland French towns
On a normal July day the thermometer tops out near 27.1°C. By rainfall alone, it ranks wetter than 79% of mainland French towns. Only 28°C separates winter nights from summer afternoons. The outdoor season, with highs of 20–27°C, runs through May, June, August and September.
These are the figures of Météo-France’s Grenoble-Saint-Geoirs station, 19 km west.
A year in Saint-Cassien at a glance
Each month’s typical high and low in °C, at the Grenoble-Saint-Geoirs station.
What a year in Saint-Cassien feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Grenoble-Saint-Geoirs.
About 915 mm of rain a year
October is the wettest month and February the driest. About 29 days a year bring 10 mm or more. 67th wettest of 110 towns of 2,500+ in Isère.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Grenoble-Saint-Geoirs
A frosty town: 66 frosts and 70 days of 25°C a year
On about 66 nights a year the air drops to 0°C or below, and on about 7 days it stays below freezing all day. About 70 days a year reach 25°C, and 21 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Grenoble-Saint-Geoirs: 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 Grenoble-Saint-Geoirs
Grenoble-Saint-Geoirs is 19 km west of Saint-Cassien. Every figure on this page is the station’s, not a measurement in Saint-Cassien itself.
| Station (Météo-France number) | Grenoble-Saint-Geoirs (38384001) |
| Distance from the town | 19 km west |
| Station altitude | 376 m |
| Town altitude (its center) | 362 m |
| Period | 1991–2020 |
| Nearest station of any kind | 3.4 km |
| Sunshine measured at | the same station |
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 Saint-Cassien 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 Isère.
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 |
|---|---|---|---|---|
| Saint-Cassien | Grenoble-Saint-Geoirs | 27.1°C | −0.7°C | 915 mm |
| Voiron 2.6 km | Pont-de-Beauvoisin | 28.5°C 1.4°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
| Saint-Jean-de-Moirans 3.4 km | Pont-de-Beauvoisin | 28.5°C 1.4°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
| Moirans 3.8 km | Pont-de-Beauvoisin | 28.5°C 1.4°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
| Rives 4.3 km | same station | 27.1°C about the same | −0.7°C about the same | 915 mm |
| Coublevie 4.5 km | Pont-de-Beauvoisin | 28.5°C 1.4°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
| La Buisse 5.5 km | Pont-de-Beauvoisin | 28.5°C 1.4°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
Saint-Cassien weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Grenoble-Saint-Geoirs station.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.3°C | −0.7°C | 2.8°C | 63 mm | 91 |
| February | 8.0°C | −0.5°C | 3.8°C | 49 mm | 112 |
| March | 12.6°C | 2.1°C | 7.4°C | 63 mm | 173 |
| April | 16.2°C | 4.7°C | 10.4°C | 76 mm | 190 |
| May | 20.2°C | 8.9°C | 14.5°C | 91 mm | 221 |
| June | 24.4°C | 12.4°C | 18.4°C | 73 mm | 258 |
| July | 27.1°C | 14.1°C | 20.6°C | 67 mm | 292 |
| August | 26.9°C | 14.2°C | 20.5°C | 66 mm | 263 |
| September | 22.0°C | 10.8°C | 16.4°C | 99 mm | 199 |
| October | 17.0°C | 7.7°C | 12.3°C | 107 mm | 140 |
| November | 10.7°C | 3.2°C | 6.9°C | 99 mm | 91 |
| December | 6.9°C | 0.1°C | 3.5°C | 64 mm | 78 |
| Year | 16.5°C | 6.4°C | 11.5°C | 915 mm | 2,108 |
Where Saint-Cassien’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Grenoble-Saint-Geoirs, 19 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, Grenoble-Saint-Geoirs, 19 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 Isère.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Saint-Cassien’s climate
How warm does Saint-Cassien get in summer?
July is the warmest month, with average highs of 27.1°C. About 70 days a year reach 25°C, more than 64% of mainland French towns, and about 21 reach 30°C.
How cold does Saint-Cassien get in winter?
January nights average −0.7°C. The air drops to 0°C or below on about 66 nights a year, and about 7 days a year stay below freezing all day.
How much rain does Saint-Cassien get?
About 915 mm a year, more than 79% of mainland French towns. October is the wettest month (107 mm) and February the driest (49 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Grenoble-Saint-Geoirs (19 km away), averages 2,108 hours of sunshine a year.
Are these figures for Saint-Cassien itself?
No: they are the normals of the Météo-France station matched to Saint-Cassien, Grenoble-Saint-Geoirs, 19 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 GRENOBLE-ST GEOIRS, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Saint-Cassien →
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.