Wet weather: 1,033 mm a year falls on Saint-Just, more than on 89% of mainland French towns
On a normal July day the thermometer tops out near 26.6°C. Expect the heaviest rain in November and the lightest in February. About 65 nights a year bring a frost, more than in 87% of mainland French towns. Long walks are most pleasant from May to October, when afternoons reach 17–27°C.
These are the figures of Météo-France’s Ceyzériat station, 1.2 km north.
A year in Saint-Just at a glance
Each month’s typical high and low in °C, at the Ceyzériat station.
What a year in Saint-Just feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Ceyzériat.
About 1,033 mm of rain a year
November is the wettest month and February the driest. About 34 days a year bring 10 mm or more. 20th wettest of 60 towns of 2,500+ in Ain.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Amberieu
A frosty town: 65 frosts and 69 days of 25°C a year
On about 65 nights a year the air drops to 0°C or below, and on about 9 days it stays below freezing all day. About 69 days a year reach 25°C, and 20 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Ceyzériat: 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 Ceyzériat
Ceyzériat is 1.2 km north of Saint-Just. Every figure on this page is the station’s, not a measurement in Saint-Just itself.
| Station (Météo-France number) | Ceyzériat (01072001) |
| Distance from the town | 1.2 km north |
| Station altitude | 260 m |
| Town altitude (its center) | 257 m |
| Period | 1994–2020 (the station’s own record) |
| 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 Saint-Just 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 |
|---|---|---|---|---|
| Saint-Just | Ceyzériat | 26.6°C | 0.1°C | 1,033 mm |
| Ceyzériat 3.4 km | same station | 26.6°C about the same | 0.1°C about the same | 1,033 mm |
| Bourg-en-Bresse 4.2 km | same station | 26.6°C about the same | 0.1°C about the same | 1,033 mm |
| Péronnas 5.6 km | same station | 26.6°C about the same | 0.1°C about the same | 1,033 mm |
| Saint-Denis-lès-Bourg 6.5 km | same station | 26.6°C about the same | 0.1°C about the same | 1,033 mm |
| Viriat 7.4 km | same station | 26.6°C about the same | 0.1°C about the same | 1,033 mm |
| Saint-Étienne-du-Bois 9.9 km | same station | 26.6°C about the same | 0.1°C about the same | 1,033 mm |
Saint-Just weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Ceyzériat station; sunshine at Amberieu.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.1°C | 0.1°C | 3.1°C | 81 mm | 68 |
| February | 8.1°C | 0.2°C | 4.1°C | 69 mm | 98 |
| March | 12.9°C | 2.3°C | 7.6°C | 75 mm | 170 |
| April | 16.9°C | 5.4°C | 11.2°C | 86 mm | 194 |
| May | 20.8°C | 9.3°C | 15.1°C | 101 mm | 220 |
| June | 24.7°C | 12.7°C | 18.7°C | 76 mm | 252 |
| July | 26.6°C | 14.2°C | 20.4°C | 81 mm | 288 |
| August | 26.4°C | 13.9°C | 20.1°C | 87 mm | 261 |
| September | 21.9°C | 10.6°C | 16.2°C | 80 mm | 189 |
| October | 17.0°C | 8.2°C | 12.6°C | 104 mm | 122 |
| November | 10.5°C | 3.6°C | 7.0°C | 108 mm | 73 |
| December | 6.7°C | 0.9°C | 3.8°C | 87 mm | 55 |
| Year | 16.5°C | 6.8°C | 11.7°C | 1,033 mm | 1,989 |
Where Saint-Just’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Ceyzériat, 1.2 km away: statistics for 1991–2020 (the station’s own years, 1994–2020, where its record is shorter).
- 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 Saint-Just’s climate
How warm does Saint-Just get in summer?
July is the warmest month, with average highs of 26.6°C. About 69 days a year reach 25°C, more than 61% of mainland French towns, and about 20 reach 30°C.
How cold does Saint-Just get in winter?
January nights average 0.1°C. The air drops to 0°C or below on about 65 nights a year, and about 9 days a year stay below freezing all day.
How much rain does Saint-Just get?
About 1,033 mm a year, more than 89% of mainland French towns. November is the wettest month (108 mm) and February the driest (69 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 Saint-Just itself?
No: they are the normals of the Météo-France station matched to Saint-Just, Ceyzériat, 1.2 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 CEYZERIAT_SAPC, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Saint-Just →
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.