Châteaulin climate — normals and trends
Châteaulin (France) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 11.1 °C and it receives 883 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (16.8 °C on average) and the coldest is January (6.0 °C). Rainfall peaks in December.
Châteaulin averages 20 frost days, 1 hot days (≥ 30 °C) and 146 rainy days per year.
Châteaulin has warmed by +1.1 °C between 1940 and 2025, or +0.13 °C per decade. This trend is statistically significant.
The number of frost days there went from about 26 to 14 per year over the period.
The hottest day of the period reached 38.6 °C (on 18 July 2022) and the coldest -12.2 °C (on 16 January 1985).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
ChâteaulinBrittany Region
- coords
- 48.20°, -4.09°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
11.1°C
Average daily high
14.4°C
Average daily low
8.1°C
Annual rainfall
883mm
Sunshine / day
8.7h
Mean relative humidity
82%
Average peak wind
20.4km/h
Seasonal range
10.8°C
Frost days (< 0 °C)
20 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
146 d/yr
Annual snowfall
3.6 cm
Average feels-like high
12.3 °C
Average feels-like low
5.5 °C
Average peak gust
43.0 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
12.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.1 °C
since 1940
+0.1 °C per decade · r² = 0.28 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
38.6 °C
18 July 2022
Coldest day
-12.2 °C
16 January 1985
Wettest day
49 mm
21 August 1944
Windiest day
69.9 km/h
2 November 2023
Strongest gust
139.3 km/h
16 October 1987
Hottest feels-like
39.3 °C
9 August 2003
Coldest feels-like
-16.6 °C
13 January 1987
Snowiest day
8.8 cm
19 February 1963
Sunniest day
15.4 h
18 June 1945
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 8.9 °C | +0.6 °C | 181 mm | +87 mm |
| Feb | 10.0 °C | +1.1 °C | 53 mm | -27 mm |
| Mar | 12.7 °C | +1.6 °C | 32 mm | -43 mm |
| Apr | 17.0 °C | +3.8 °C | 86 mm | +18 mm |
| May | 18.2 °C | +2.2 °C | 77 mm | +3 mm |
| Jun | 22.1 °C | +3.3 °C | 45 mm | -10 mm |
| Jul | 22.2 °C | +1.6 °C | 45 mm | -3 mm |
| Aug | 23.3 °C | +2.7 °C | 52 mm | -3 mm |
| Sep | 17.9 °C | -0.8 °C | 83 mm | +21 mm |
| Oct | 16.4 °C | +1.0 °C | 79 mm | -2 mm |
| Nov | 13.1 °C | +1.7 °C | 104 mm | +11 mm |
| Dec | 10.2 °C | +1.0 °C | 126 mm | +25 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Châteaulin?
Châteaulin has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 11.1 °C and it receives 883 mm of precipitation per year.
What is the hottest day ever recorded in Châteaulin?
The hottest day measured in Châteaulin between 1940 and 2025 was 18 July 2022, reaching 38.6 °C.
What is the coldest day in Châteaulin?
The coldest day measured in Châteaulin between 1940 and 2025 was 16 January 1985, at -12.2 °C.
Does it snow in Châteaulin?
Yes. Châteaulin gets on average 3.6 cm of snow per year and has around 20 frost days.
Has the climate of Châteaulin warmed?
Yes: Châteaulin warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Châteaulin?
The wettest day measured in Châteaulin between 1940 and 2025 was 21 August 1944, with 49 mm of rain in 24 hours.
What was the windiest day in Châteaulin?
The windiest day measured in Châteaulin between 1940 and 2025 was 2 November 2023, with winds reaching 69.9 km/h.
What is the warmest month in Châteaulin?
The warmest month in Châteaulin is July (16.8 °C on average); the coldest is January (6.0 °C).
How much does it rain in Châteaulin?
Châteaulin receives on average 883 mm of precipitation per year, spread over about 146 rainy days.
Is it sunny in Châteaulin?
Châteaulin gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.
What is the biggest single-day snowfall in Châteaulin?
The heaviest 24-hour snowfall measured in Châteaulin between 1940 and 2025 was 19 February 1963, with 8.8 cm.
Are there tropical nights in Châteaulin?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Châteaulin.
What was the most extreme apparent temperature in Châteaulin?
In Châteaulin, between 1940 and 2025, the highest apparent temperature reached 39.3 °C on 9 August 2003, and the lowest was -16.6 °C on 13 January 1987.
Compare Châteaulin with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Châteaulin