Summers in Trégarvan are cooler than in 94% of mainland French towns
Nights in January average 3.9°C. Temperatures cover 19°C across the year, low to high. By rainfall alone, it ranks wetter than 93% of mainland French towns. Frost greets about 31 mornings a year, so leave time to clear the car.
Figures from Météo-France’s Saint-Ségal S A station, 10 km east.
A year in Trégarvan at a glance
Each month’s typical high and low in °C, at the Saint-Ségal S A station.
What a year in Trégarvan feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Saint-Ségal S A.
About 1,126 mm of rain a year
December is the wettest month and June the driest. About 37 days a year bring 10 mm or more. 53rd wettest of 91 towns of 2,500+ in Finistère.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Lanvéoc
31 frosts and 23 days of 25°C a year
On about 31 nights a year the air drops to 0°C or below; days that stay below freezing are rare. About 23 days a year reach 25°C, and 3 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Saint-Ségal S A: 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-Ségal S A
Saint-Ségal S A is 10 km east of Trégarvan. Every figure on this page is the station’s, not a measurement in Trégarvan itself.
| Station (Météo-France number) | Saint-Ségal S A (29263002) |
| Distance from the town | 10 km east |
| Station altitude | 89 m |
| Town altitude (its center) | 58 m |
| Period | 1991–2020 |
| Sunshine measured at | Lanvéoc, 17 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 Trégarvan 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 Finistère.
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 |
|---|---|---|---|---|
| Trégarvan | Saint-Ségal S A | 22.5°C | 3.9°C | 1,126 mm |
| Pont-de-Buis-lès-Quimerch 9.6 km | same station | 22.5°C about the same | 3.9°C about the same | 1,126 mm |
| Châteaulin 11 km | same station | 22.5°C about the same | 3.9°C about the same | 1,126 mm |
| Loperhet 16 km | Brest-Guipavas | 20.8°C 1.7°C cooler | 4.6°C 0.7°C milder | 1,230 mm |
| Plougastel-Daoulas 18 km | Brest-Guipavas | 20.8°C 1.7°C cooler | 4.6°C 0.7°C milder | 1,230 mm |
| Pleyben 19 km | same station | 22.5°C about the same | 3.9°C about the same | 1,126 mm |
| Douarnenez 19 km | Plomelin-Inrae | 22.2°C about the same | 4.3°C about the same | 1,150 mm |
Trégarvan weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Saint-Ségal S A station; sunshine at Lanvéoc.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 9.8°C | 3.9°C | 6.9°C | 130 mm | 61 |
| February | 10.4°C | 3.5°C | 7.0°C | 107 mm | 81 |
| March | 12.6°C | 4.5°C | 8.5°C | 77 mm | 124 |
| April | 15.0°C | 5.4°C | 10.2°C | 84 mm | 164 |
| May | 18.1°C | 8.2°C | 13.1°C | 70 mm | 192 |
| June | 20.8°C | 10.8°C | 15.8°C | 59 mm | 208 |
| July | 22.5°C | 12.7°C | 17.6°C | 65 mm | 194 |
| August | 22.6°C | 12.5°C | 17.6°C | 68 mm | 190 |
| September | 20.5°C | 10.4°C | 15.5°C | 76 mm | 175 |
| October | 16.7°C | 8.9°C | 12.8°C | 118 mm | 112 |
| November | 12.8°C | 6.1°C | 9.5°C | 132 mm | 71 |
| December | 10.4°C | 4.3°C | 7.4°C | 141 mm | 65 |
| Year | 16.0°C | 7.6°C | 11.8°C | 1,126 mm | 1,636 |
Where Trégarvan’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Saint-Ségal S A, 10 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, Lanvéoc, 17 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 Finistère.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Trégarvan’s climate
How warm does Trégarvan get in summer?
August is the warmest month, with average highs of 22.6°C. About 23 days a year reach 25°C, fewer than 94% of mainland French towns, and about 3 reach 30°C.
How cold does Trégarvan get in winter?
February nights average 3.5°C. The air drops to 0°C or below on about 31 nights a year, and about under 1 days a year stay below freezing all day.
How much rain does Trégarvan get?
About 1,126 mm a year, more than 93% of mainland French towns. December is the wettest month (141 mm) and June the driest (59 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Lanvéoc (17 km away), averages 1,636 hours of sunshine a year.
Are these figures for Trégarvan itself?
No: they are the normals of the Météo-France station matched to Trégarvan, Saint-Ségal S A, 10 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 ST-SEGAL S A, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Trégarvan →
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.