Afternoon heat in Cast trails that of 94% of mainland French towns
Deep winter brings January lows near 3.9°C. The rainiest month is December; the driest is June. By rainfall alone, it ranks wetter than 93% of mainland French towns. Expect about 31 frosty starts a year, nights when the air falls below freezing.
Figures from Météo-France’s Saint-Ségal S A station, 8.9 km north.
A year in Cast at a glance
Each month’s typical high and low in °C, at the Saint-Ségal S A station.
What a year in Cast 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 Quimper
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 8.9 km north of Cast. Every figure on this page is the station’s, not a measurement in Cast itself.
| Station (Météo-France number) | Saint-Ségal S A (29263002) |
| Distance from the town | 8.9 km north |
| Station altitude | 89 m |
| Town altitude (its center) | 95 m |
| Period | 1991–2020 |
| Sunshine measured at | Quimper, 20 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 Cast 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 |
|---|---|---|---|---|
| Cast | Saint-Ségal S A | 22.5°C | 3.9°C | 1,126 mm |
| Châteaulin 6.2 km | same station | 22.5°C about the same | 3.9°C about the same | 1,126 mm |
| Plogonnec 9.1 km | Quimper | 21.8°C 0.7°C cooler | 4.5°C 0.6°C milder | 1,214 mm |
| Briec 11 km | same station | 22.5°C about the same | 3.9°C about the same | 1,126 mm |
| Pont-de-Buis-lès-Quimerch 13 km | same station | 22.5°C about the same | 3.9°C about the same | 1,126 mm |
| Pleyben 15 km | same station | 22.5°C about the same | 3.9°C about the same | 1,126 mm |
| Douarnenez 16 km | Plomelin-Inrae | 22.2°C about the same | 4.3°C about the same | 1,150 mm |
Cast weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Saint-Ségal S A station; sunshine at Quimper.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 9.8°C | 3.9°C | 6.9°C | 130 mm | 66 |
| February | 10.4°C | 3.5°C | 7.0°C | 107 mm | 90 |
| March | 12.6°C | 4.5°C | 8.5°C | 77 mm | 133 |
| April | 15.0°C | 5.4°C | 10.2°C | 84 mm | 177 |
| May | 18.1°C | 8.2°C | 13.1°C | 70 mm | 201 |
| June | 20.8°C | 10.8°C | 15.8°C | 59 mm | 209 |
| July | 22.5°C | 12.7°C | 17.6°C | 65 mm | 205 |
| August | 22.6°C | 12.5°C | 17.6°C | 68 mm | 195 |
| 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 | 79 |
| December | 10.4°C | 4.3°C | 7.4°C | 141 mm | 67 |
| Year | 16.0°C | 7.6°C | 11.8°C | 1,126 mm | 1,708 |
Where Cast’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, 8.9 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, Quimper, 20 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 Cast’s climate
How warm does Cast 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 Cast 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 Cast 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, Quimper (20 km away), averages 1,708 hours of sunshine a year.
Are these figures for Cast itself?
No: they are the normals of the Météo-France station matched to Cast, Saint-Ségal S A, 8.9 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 Cast →
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.