Hardly any mainland French towns collect more rain than Seillonnaz: 1,512 mm a year
High summer brings afternoon highs near 27.6°C. About 76 nights a year bring a frost, more than in 93% of mainland French towns. Rain peaks in November and eases off in August. The heating season runs November to March: each of those months averages under 10°C.
These are the figures of Météo-France’s Saint-Rambert-en-Bugey station, 17 km north.
A year in Seillonnaz at a glance
Each month’s typical high and low in °C, at the Saint-Rambert-en-Bugey station.
What a year in Seillonnaz feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Saint-Rambert-en-Bugey.
About 1,512 mm of rain a year
November is the wettest month and August the driest. About 52 days a year bring 10 mm or more. 8th wettest of 60 towns of 2,500+ in Ain.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Amberieu
A frosty town: 76 frosts and 81 days of 25°C a year
On about 76 nights a year the air drops to 0°C or below, and on about 7 days it stays below freezing all day. About 81 days a year reach 25°C, and 28 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Saint-Rambert-en-Bugey: 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 Saint-Rambert-en-Bugey
Saint-Rambert-en-Bugey is 17 km north of Seillonnaz. Every figure on this page is the station’s, not a measurement in Seillonnaz itself.
| Station (Météo-France number) | Saint-Rambert-en-Bugey (01384001) |
| Distance from the town | 17 km north |
| Station altitude | 287 m |
| Town altitude (its center) | 378 m |
| Period | 1991–2020 |
| Nearest station of any kind | 1.7 km |
| Sunshine measured at | Amberieu, 24 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 Seillonnaz 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 Ain.
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 |
|---|---|---|---|---|
| Seillonnaz | Saint-Rambert-en-Bugey | 27.6°C | −0.7°C | 1,512 mm |
| Montalieu-Vercieu 7.2 km | same station | 27.6°C about the same | −0.7°C about the same | 1,512 mm |
| Morestel 12 km | Pont-de-Beauvoisin | 28.5°C 0.9°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
| Belley 16 km | Chambery-Aix | 27.8°C about the same | −0.7°C about the same | 1,204 mm |
| Lagnieu 17 km | Amberieu | 27.5°C about the same | −0.1°C 0.6°C milder | 1,118 mm |
| Les Avenières Veyrins-Thuellin 18 km | Pont-de-Beauvoisin | 28.5°C 0.9°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
| Dolomieu 19 km | Pont-de-Beauvoisin | 28.5°C 0.9°C warmer | −1.2°C 0.5°C colder | 1,166 mm |
Seillonnaz weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Saint-Rambert-en-Bugey station; sunshine at Amberieu.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.0°C | −0.7°C | 2.6°C | 134 mm | 68 |
| February | 8.2°C | −0.7°C | 3.8°C | 114 mm | 98 |
| March | 13.5°C | 1.6°C | 7.5°C | 112 mm | 170 |
| April | 17.4°C | 4.6°C | 11.0°C | 123 mm | 194 |
| May | 21.5°C | 8.4°C | 14.9°C | 135 mm | 220 |
| June | 25.3°C | 11.5°C | 18.4°C | 105 mm | 252 |
| July | 27.6°C | 13.2°C | 20.4°C | 108 mm | 288 |
| August | 27.2°C | 12.9°C | 20.1°C | 99 mm | 261 |
| September | 22.4°C | 9.8°C | 16.1°C | 128 mm | 189 |
| October | 17.1°C | 7.1°C | 12.1°C | 151 mm | 122 |
| November | 10.4°C | 2.9°C | 6.7°C | 159 mm | 73 |
| December | 6.2°C | 0.2°C | 3.2°C | 145 mm | 55 |
| Year | 16.9°C | 5.9°C | 11.4°C | 1,512 mm | 1,989 |
Where Seillonnaz’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Saint-Rambert-en-Bugey, 17 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, Amberieu, 24 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 Ain.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Seillonnaz’s climate
How warm does Seillonnaz get in summer?
July is the warmest month, with average highs of 27.6°C. About 81 days a year reach 25°C, more than 72% of mainland French towns, and about 28 reach 30°C.
How cold does Seillonnaz get in winter?
January nights average −0.7°C. The air drops to 0°C or below on about 76 nights a year, and about 7 days a year stay below freezing all day.
How much rain does Seillonnaz get?
About 1,512 mm a year, more than almost every mainland French town. November is the wettest month (159 mm) and August the driest (99 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Amberieu (24 km away), averages 1,989 hours of sunshine a year.
Are these figures for Seillonnaz itself?
No: they are the normals of the Météo-France station matched to Seillonnaz, Saint-Rambert-en-Bugey, 17 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 SAINT RAMBERT EN BUGEY, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Seillonnaz →
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.