Afternoon heat in Treffrin trails that of 92% of mainland French towns
January mornings start at about 3.2°C. Rain is plentiful here, more than falls on 92% of mainland French towns. Wet weather is most frequent in December and least in June. The outdoor season runs from June to September, with highs of 21–23°C.
These are the figures of Météo-France’s Carhaix station, 2.2 km south.
A year in Treffrin at a glance
Each month’s typical high and low in °C, at the Carhaix station.
What a year in Treffrin feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Carhaix.
About 1,112 mm of rain a year
December is the wettest month and June the driest. About 34 days a year bring 10 mm or more. 2nd wettest of 61 towns of 2,500+ in Côtes-d'Armor.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Landivisiau
39 frosts and 30 days of 25°C a year
On about 39 nights a year the air drops to 0°C or below, and on about under 1 days it stays below freezing all day. About 30 days a year reach 25°C, and 5 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Carhaix: 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 Carhaix
Carhaix is 2.2 km south of Treffrin. Every figure on this page is the station’s, not a measurement in Treffrin itself.
| Station (Météo-France number) | Carhaix (29024003) |
| Distance from the town | 2.2 km south |
| Station altitude | 150 m |
| Town altitude (its center) | 132 m |
| Period | 1991–2020 |
| Sunshine measured at | Landivisiau, 53 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 Treffrin 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 Côtes-d'Armor.
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 |
|---|---|---|---|---|
| Treffrin | Carhaix | 22.9°C | 3.2°C | 1,112 mm |
| Carhaix-Plouguer 4 km | same station | 22.9°C about the same | 3.2°C about the same | 1,112 mm |
| Rostrenen 17 km | Rostrenen | 21.7°C 1.2°C cooler | 3.1°C about the same | 1,147 mm |
| Gourin 18 km | Guiscriff | 22.9°C about the same | 3.3°C about the same | 1,366 mm |
| Châteauneuf-du-Faou 25 km | Coray Chat Eau | 21.8°C 1.1°C cooler | 3.3°C about the same | 1,423 mm |
| Le Faouët 29 km | Lanvénégen | 23.7°C 0.8°C warmer | 3.3°C about the same | 1,215 mm |
Treffrin weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Carhaix station; sunshine at Landivisiau.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 9.1°C | 3.2°C | 6.1°C | 132 mm | 60 |
| February | 10.0°C | 2.8°C | 6.4°C | 110 mm | 74 |
| March | 12.5°C | 3.8°C | 8.1°C | 79 mm | 110 |
| April | 15.1°C | 4.8°C | 9.9°C | 81 mm | 143 |
| May | 18.2°C | 7.5°C | 12.9°C | 75 mm | 171 |
| June | 21.1°C | 10.1°C | 15.6°C | 56 mm | 183 |
| July | 22.9°C | 11.9°C | 17.4°C | 59 mm | 169 |
| August | 22.9°C | 11.9°C | 17.4°C | 62 mm | 165 |
| September | 20.6°C | 9.8°C | 15.2°C | 74 mm | 154 |
| October | 16.4°C | 8.1°C | 12.2°C | 112 mm | 105 |
| November | 12.3°C | 5.4°C | 8.8°C | 127 mm | 68 |
| December | 9.6°C | 3.6°C | 6.6°C | 145 mm | 62 |
| Year | 15.9°C | 6.9°C | 11.4°C | 1,112 mm | 1,463 |
Where Treffrin’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Carhaix, 2.2 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, 53 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 Côtes-d'Armor.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Treffrin’s climate
How warm does Treffrin get in summer?
July is the warmest month, with average highs of 22.9°C. About 30 days a year reach 25°C, fewer than 92% of mainland French towns, and about 5 reach 30°C.
How cold does Treffrin get in winter?
February nights average 2.8°C. The air drops to 0°C or below on about 39 nights a year, and about under 1 days a year stay below freezing all day.
How much rain does Treffrin get?
About 1,112 mm a year, more than 92% of mainland French towns. December is the wettest month (145 mm) and June the driest (56 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Landivisiau (53 km away), averages 1,463 hours of sunshine a year.
Are these figures for Treffrin itself?
No: they are the normals of the Météo-France station matched to Treffrin, Carhaix, 2.2 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 CARHAIX, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Treffrin →
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.