January in Plan bites harder than in 92% of mainland French towns
High summer brings afternoon highs near 27.1°C. Only 28°C separates winter nights from summer afternoons. Its yearly rainfall tops that of 79% of mainland French towns. Wet days, with 1 mm of rain or more, come about 104 times a year.
Figures from Météo-France’s Grenoble-Saint-Geoirs station, 8.4 km north-west.
A year in Plan at a glance
Each month’s typical high and low in °C, at the Grenoble-Saint-Geoirs station.
What a year in Plan 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 8.4 km north-west of Plan. Every figure on this page is the station’s, not a measurement in Plan itself.
| Station (Météo-France number) | Grenoble-Saint-Geoirs (38384001) |
| Distance from the town | 8.4 km north-west |
| Station altitude | 376 m |
| Town altitude (its center) | 596 m |
| Period | 1991–2020 |
| Sunshine measured at | the same station |
Plan sits 220 m higher than the station. Air usually cools by about 0.65°C every 100 m, so expect Plan to run about 1.4°C cooler than these figures.
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 Plan 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 |
|---|---|---|---|---|
| Plan | Grenoble-Saint-Geoirs | 27.1°C | −0.7°C | 915 mm |
| Saint-Étienne-de-Saint-Geoirs 4.8 km | same station | 27.1°C about the same | −0.7°C about the same | 915 mm |
| Tullins 7.8 km | Chatte | 28.3°C 1.2°C warmer | −0.5°C about the same | 968 mm |
| Renage 8 km | same station | 27.1°C about the same | −0.7°C about the same | 915 mm |
| Rives 9.6 km | same station | 27.1°C about the same | −0.7°C about the same | 915 mm |
| Le Grand-Lemps 9.6 km | same station | 27.1°C about the same | −0.7°C about the same | 915 mm |
| Saint-Siméon-de-Bressieux 10 km | same station | 27.1°C about the same | −0.7°C about the same | 915 mm |
Plan 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 Plan’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, 8.4 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, 8.4 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 Plan’s climate
How warm does Plan 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 Plan 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 Plan 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 (8.4 km away), averages 2,108 hours of sunshine a year.
Are these figures for Plan itself?
No: they are the normals of the Météo-France station matched to Plan, Grenoble-Saint-Geoirs, 8.4 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 Plan →
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.