Winter nights in La Trinité-Surzur are milder than in 88% of mainland French towns
Midsummer highs settle at about 23.9°C. Its July afternoons stay fresher than in 84% of mainland French towns. Seasons differ by 21°C, from the coldest nights to the warmest afternoons. Windscreens need scraping on about 32 mornings a year, the nights the air drops below 0°C.
These are the figures of Météo-France’s Billiers station, 12 km south-east.
A year in La Trinité-Surzur at a glance
Each month’s typical high and low in °C, at the Billiers station.
What a year in La Trinité-Surzur feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Billiers.
About 840 mm of rain a year
December is the wettest month and July the driest. About 27 days a year bring 10 mm or more. 80th wettest of 88 towns of 2,500+ in Morbihan.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Vannes-Séné
32 frosts and 38 days of 25°C a year
On about 32 nights a year the air drops to 0°C or below, and on about under 1 days it stays below freezing all day. About 38 days a year reach 25°C, and 8 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Billiers: 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 Billiers
Billiers is 12 km south-east of La Trinité-Surzur. Every figure on this page is the station’s, not a measurement in La Trinité-Surzur itself.
| Station (Météo-France number) | Billiers (56018001) |
| Distance from the town | 12 km south-east |
| Station altitude | 4 m |
| Town altitude (its center) | 34 m |
| Period | 1991–2020 |
| Nearest station of any kind | 9.1 km |
| Sunshine measured at | Vannes-Séné, 9.1 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 La Trinité-Surzur 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 Morbihan.
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 |
|---|---|---|---|---|
| La Trinité-Surzur | Billiers | 23.9°C | 3.7°C | 840 mm |
| Surzur 4.2 km | same station | 23.9°C about the same | 3.7°C about the same | 840 mm |
| Theix-Noyalo 5.5 km | Saint-Avé | 24.9°C 1°C warmer | 3.6°C about the same | 1,034 mm |
| Sulniac 6.9 km | Questembert | 24.2°C about the same | 3.0°C 0.7°C colder | 1,096 mm |
| Treffléan 8.6 km | Questembert | 24.2°C about the same | 3.0°C 0.7°C colder | 1,096 mm |
| Muzillac 10 km | same station | 23.9°C about the same | 3.7°C about the same | 840 mm |
| Noyal-Muzillac 10 km | Questembert | 24.2°C about the same | 3.0°C 0.7°C colder | 1,096 mm |
La Trinité-Surzur weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Billiers station; sunshine at Vannes-Séné.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 9.6°C | 3.7°C | 6.6°C | 94 mm | 75 |
| February | 10.5°C | 3.3°C | 6.9°C | 74 mm | 107 |
| March | 13.2°C | 4.8°C | 9.0°C | 60 mm | 157 |
| April | 15.9°C | 6.2°C | 11.1°C | 61 mm | 201 |
| May | 19.1°C | 9.6°C | 14.4°C | 61 mm | 222 |
| June | 22.1°C | 12.3°C | 17.2°C | 45 mm | 244 |
| July | 23.9°C | 13.9°C | 18.9°C | 42 mm | 255 |
| August | 24.0°C | 13.7°C | 18.8°C | 52 mm | 225 |
| September | 21.7°C | 11.3°C | 16.5°C | 63 mm | 202 |
| October | 17.5°C | 9.4°C | 13.4°C | 87 mm | 121 |
| November | 13.2°C | 6.1°C | 9.6°C | 99 mm | 93 |
| December | 10.3°C | 3.8°C | 7.0°C | 103 mm | 79 |
| Year | 16.7°C | 8.2°C | 12.4°C | 840 mm | 1,981 |
Where La Trinité-Surzur’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Billiers, 12 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, Vannes-Séné, 9.1 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 Morbihan.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about La Trinité-Surzur’s climate
How warm does La Trinité-Surzur get in summer?
August is the warmest month, with average highs of 24.0°C. About 38 days a year reach 25°C, fewer than 82% of mainland French towns, and about 8 reach 30°C.
How cold does La Trinité-Surzur get in winter?
February nights average 3.3°C. The air drops to 0°C or below on about 32 nights a year, and about under 1 days a year stay below freezing all day.
How much rain does La Trinité-Surzur get?
About 840 mm a year, more than 69% of mainland French towns. December is the wettest month (103 mm) and July the driest (42 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Vannes-Séné (9.1 km away), averages 1,981 hours of sunshine a year.
Are these figures for La Trinité-Surzur itself?
No: they are the normals of the Météo-France station matched to La Trinité-Surzur, Billiers, 12 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 BILLIERS, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for La Trinité-Surzur →
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.