Rainfall in Saint-Gonlay tops that of 74% of mainland French towns: 873 mm a year
July afternoons average 25.4°C. Its January nights stay gentler than in 72% of mainland French towns. December is the wettest month, July the driest. Frost greets about 40 mornings a year, so leave time to clear the car.
These are the figures of Météo-France’s Guer station, 24 km south.
A year in Saint-Gonlay at a glance
Each month’s typical high and low in °C, at the Guer station.
What a year in Saint-Gonlay feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Guer.
About 873 mm of rain a year
December is the wettest month and July the driest. About 27 days a year bring 10 mm or more. 14th wettest of 99 towns of 2,500+ in Ille-et-Vilaine.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Rennes-Saint-Jacques
40 frosts and 56 days of 25°C a year
On about 40 nights a year the air drops to 0°C or below, and on about under 1 days it stays below freezing all day. About 56 days a year reach 25°C, and 14 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Guer: 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 Guer
Guer is 24 km south of Saint-Gonlay. Every figure on this page is the station’s, not a measurement in Saint-Gonlay itself.
| Station (Météo-France number) | Guer (56075001) |
| Distance from the town | 24 km south |
| Station altitude | 47 m |
| Town altitude (its center) | 45 m |
| Period | 1992–2020 (the station’s own record) |
| Nearest station of any kind | 22 km |
| Sunshine measured at | Rennes-Saint-Jacques, 26 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-Gonlay 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 Ille-et-Vilaine.
Nearby towns’ climate
The nearest towns of 2,500+ within 29 km, each with its own matched station.
| Town | Station | July high | January low | Rain a year |
|---|---|---|---|---|
| Saint-Gonlay | Guer | 25.4°C | 2.9°C | 873 mm |
| Iffendic 3.6 km | Rennes-Saint-Jacques | 24.8°C 0.6°C cooler | 3.3°C about the same | 691 mm |
| Montfort-sur-Meu 9.1 km | Rennes-Saint-Jacques | 24.8°C 0.6°C cooler | 3.3°C about the same | 691 mm |
| Montauban-de-Bretagne 10 km | Le Quiou | 24.7°C 0.7°C cooler | 3.0°C about the same | 757 mm |
| Talensac 11 km | Rennes-Saint-Jacques | 24.8°C 0.6°C cooler | 3.3°C about the same | 691 mm |
| Saint-Méen-le-Grand 12 km | Le Quiou | 24.7°C 0.7°C cooler | 3.0°C about the same | 757 mm |
| Bédée 12 km | Rennes-Saint-Jacques | 24.8°C 0.6°C cooler | 3.3°C about the same | 691 mm |
Saint-Gonlay weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Guer station; sunshine at Rennes-Saint-Jacques.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 9.5°C | 2.9°C | 6.2°C | 99 mm | 68 |
| February | 10.8°C | 2.7°C | 6.7°C | 74 mm | 93 |
| March | 13.7°C | 3.9°C | 8.8°C | 64 mm | 134 |
| April | 16.7°C | 5.4°C | 11.0°C | 63 mm | 174 |
| May | 20.1°C | 8.7°C | 14.4°C | 61 mm | 202 |
| June | 23.4°C | 11.5°C | 17.5°C | 55 mm | 213 |
| July | 25.4°C | 13.0°C | 19.2°C | 46 mm | 220 |
| August | 25.3°C | 12.9°C | 19.1°C | 47 mm | 207 |
| September | 22.6°C | 10.4°C | 16.5°C | 62 mm | 181 |
| October | 17.7°C | 8.4°C | 13.0°C | 94 mm | 117 |
| November | 12.9°C | 5.2°C | 9.1°C | 101 mm | 84 |
| December | 9.9°C | 3.2°C | 6.6°C | 106 mm | 69 |
| Year | 17.3°C | 7.3°C | 12.3°C | 873 mm | 1,762 |
Where Saint-Gonlay’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Guer, 24 km away: statistics for 1991–2020 (the station’s own years, 1992–2020, 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, Rennes-Saint-Jacques, 26 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 Ille-et-Vilaine.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Saint-Gonlay’s climate
How warm does Saint-Gonlay get in summer?
July is the warmest month, with average highs of 25.4°C. About 56 days a year reach 25°C, fewer than 61% of mainland French towns, and about 14 reach 30°C.
How cold does Saint-Gonlay get in winter?
February nights average 2.7°C. The air drops to 0°C or below on about 40 nights a year, and about under 1 days a year stay below freezing all day.
How much rain does Saint-Gonlay get?
About 873 mm a year, more than 74% of mainland French towns. December is the wettest month (106 mm) and July the driest (46 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Rennes-Saint-Jacques (26 km away), averages 1,762 hours of sunshine a year.
Are these figures for Saint-Gonlay itself?
No: they are the normals of the Météo-France station matched to Saint-Gonlay, Guer, 24 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 GUER, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Saint-Gonlay →
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.