Wet weather: 873 mm a year falls on Tréal, more than on 74% of mainland French towns
The coldest hours of a January night bottom out at 2.9°C on average. Of all months, December brings the most rain and July the least. Its January nights stay gentler than in 72% of mainland French towns. Comfortable outdoor weather lasts from May to October, with highs of 18–25°C.
Figures from Météo-France’s Guer station, 11 km north-east.
A year in Tréal at a glance
Each month’s typical high and low in °C, at the Guer station.
What a year in Tréal 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. 78th wettest of 88 towns of 2,500+ in Morbihan.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Vannes-Séné
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 11 km north-east of Tréal. Every figure on this page is the station’s, not a measurement in Tréal itself.
| Station (Météo-France number) | Guer (56075001) |
| Distance from the town | 11 km north-east |
| Station altitude | 47 m |
| Town altitude (its center) | 58 m |
| Period | 1992–2020 (the station’s own record) |
| Sunshine measured at | Vannes-Séné, 45 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 Tréal 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 |
|---|---|---|---|---|
| Tréal | Guer | 25.4°C | 2.9°C | 873 mm |
| Carentoir 8 km | same station | 25.4°C about the same | 2.9°C about the same | 873 mm |
| La Gacilly 11 km | Saint-Jacut-les-Pins | 24.8°C 0.6°C cooler | 3.4°C 0.5°C milder | 948 mm |
| Guer 12 km | same station | 25.4°C about the same | 2.9°C about the same | 873 mm |
| Malestroit 12 km | Pleucadeuc | 24.3°C 1.1°C cooler | 3.1°C about the same | 907 mm |
| Val d'Oust 16 km | Ploërmel | 24.2°C 1.2°C cooler | 3.3°C about the same | 767 mm |
| Ploërmel 16 km | Ploërmel | 24.2°C 1.2°C cooler | 3.3°C about the same | 767 mm |
Tréal weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Guer station; sunshine at Vannes-Séné.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 9.5°C | 2.9°C | 6.2°C | 99 mm | 75 |
| February | 10.8°C | 2.7°C | 6.7°C | 74 mm | 107 |
| March | 13.7°C | 3.9°C | 8.8°C | 64 mm | 157 |
| April | 16.7°C | 5.4°C | 11.0°C | 63 mm | 201 |
| May | 20.1°C | 8.7°C | 14.4°C | 61 mm | 222 |
| June | 23.4°C | 11.5°C | 17.5°C | 55 mm | 244 |
| July | 25.4°C | 13.0°C | 19.2°C | 46 mm | 255 |
| August | 25.3°C | 12.9°C | 19.1°C | 47 mm | 225 |
| September | 22.6°C | 10.4°C | 16.5°C | 62 mm | 202 |
| October | 17.7°C | 8.4°C | 13.0°C | 94 mm | 121 |
| November | 12.9°C | 5.2°C | 9.1°C | 101 mm | 93 |
| December | 9.9°C | 3.2°C | 6.6°C | 106 mm | 79 |
| Year | 17.3°C | 7.3°C | 12.3°C | 873 mm | 1,981 |
Where Tréal’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Guer, 11 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, Vannes-Séné, 45 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 Tréal’s climate
How warm does Tréal 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 Tréal 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 Tréal 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, Vannes-Séné (45 km away), averages 1,981 hours of sunshine a year.
Are these figures for Tréal itself?
No: they are the normals of the Météo-France station matched to Tréal, Guer, 11 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 Tréal →
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.