Saint-Derrien is among the mainland French towns with the fewest days of 25 degrees or more
January nights here settle around 4.4°C. December is the wettest month, June the driest. Frosty nights are scarcer than in 96% of mainland French towns. Waterproofs come out on about 160 days a year, each with 1 mm of rain or more.
These are the figures of Météo-France’s Landivisiau station, 3 km south-east.
A year in Saint-Derrien at a glance
Each month’s typical high and low in °C, at the Landivisiau station.
What a year in Saint-Derrien feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Landivisiau.
About 1,160 mm of rain a year
December is the wettest month and June the driest. About 36 days a year bring 10 mm or more. 26th wettest of 91 towns of 2,500+ in Finistère.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Landivisiau
14 frosts and 10 days of 25°C a year
On about 14 nights a year the air drops to 0°C or below; days that stay below freezing are rare. About 10 days a year reach 25°C, and under 1 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Landivisiau: 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 Landivisiau
Landivisiau is 3 km south-east of Saint-Derrien. Every figure on this page is the station’s, not a measurement in Saint-Derrien itself.
| Station (Météo-France number) | Landivisiau (29264001) |
| Distance from the town | 3 km south-east |
| Station altitude | 109 m |
| Town altitude (its center) | 82 m |
| Period | 1991–2020 |
| Sunshine measured at | the same station |
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-Derrien 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 |
|---|---|---|---|---|
| Saint-Derrien | Landivisiau | 20.7°C | 4.4°C | 1,160 mm |
| Plouédern 9.1 km | Ploudaniel-Inrae | 21.3°C 0.6°C warmer | 4.4°C about the same | 1,147 mm |
| Landivisiau 9.2 km | same station | 20.7°C about the same | 4.4°C about the same | 1,160 mm |
| Ploudaniel 9.8 km | Ploudaniel-Inrae | 21.3°C 0.6°C warmer | 4.4°C about the same | 1,147 mm |
| Lesneven 10 km | Ploudaniel-Inrae | 21.3°C 0.6°C warmer | 4.4°C about the same | 1,147 mm |
| Le Folgoët 12 km | Ploudaniel-Inrae | 21.3°C 0.6°C warmer | 4.4°C about the same | 1,147 mm |
| Plouvorn 12 km | same station | 20.7°C about the same | 4.4°C about the same | 1,160 mm |
Saint-Derrien weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Landivisiau station.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 9.4°C | 4.4°C | 6.9°C | 140 mm | 60 |
| February | 9.8°C | 4.1°C | 6.9°C | 116 mm | 74 |
| March | 11.7°C | 5.1°C | 8.4°C | 78 mm | 110 |
| April | 13.7°C | 6.1°C | 9.9°C | 85 mm | 143 |
| May | 16.5°C | 8.7°C | 12.6°C | 72 mm | 171 |
| June | 18.9°C | 11.2°C | 15.1°C | 63 mm | 183 |
| July | 20.7°C | 13.0°C | 16.9°C | 64 mm | 169 |
| August | 20.9°C | 13.1°C | 17.0°C | 66 mm | 165 |
| September | 19.2°C | 11.5°C | 15.3°C | 73 mm | 154 |
| October | 15.9°C | 9.5°C | 12.7°C | 118 mm | 105 |
| November | 12.3°C | 6.9°C | 9.6°C | 135 mm | 68 |
| December | 10.0°C | 4.9°C | 7.5°C | 151 mm | 62 |
| Year | 14.9°C | 8.2°C | 11.6°C | 1,160 mm | 1,463 |
Where Saint-Derrien’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Landivisiau, 3 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, Landivisiau, 3 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 Saint-Derrien’s climate
How warm does Saint-Derrien get in summer?
August is the warmest month, with average highs of 20.9°C. About 10 days a year reach 25°C, fewer than almost every mainland French town, and about under 1 reach 30°C.
How cold does Saint-Derrien get in winter?
February nights average 4.1°C. The air drops to 0°C or below on about 14 nights a year, and about under 1 days a year stay below freezing all day.
How much rain does Saint-Derrien get?
About 1,160 mm a year, more than 94% of mainland French towns. December is the wettest month (151 mm) and June the driest (63 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Landivisiau (3 km away), averages 1,463 hours of sunshine a year.
Are these figures for Saint-Derrien itself?
No: they are the normals of the Météo-France station matched to Saint-Derrien, Landivisiau, 3 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 LANDIVISIAU, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Saint-Derrien →
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.