Ondarroa climate — normals and trends
Ondarroa (Spain) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 13.1 °C and it receives 1,211 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 August (19.1 °C on average) and the coldest is January (7.8 °C). Rainfall peaks in November.
Ondarroa averages 4 frost days, 1 hot days (≥ 30 °C) and 167 rainy days per year.
Ondarroa has warmed by +1.9 °C between 1940 and 2025, or +0.22 °C per decade. This trend is statistically significant.
The number of frost days there went from about 8 to 0 per year over the period.
The hottest day of the period reached 35.2 °C (on 15 August 2025) and the coldest -8.4 °C (on 16 February 1956).
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
OndarroaBasque Country
- coords
- 43.32°, -2.42°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
13.1°C
Average daily high
16.0°C
Average daily low
10.6°C
Annual rainfall
1,211mm
Sunshine / day
9.0h
Mean relative humidity
79%
Average peak wind
17.9km/h
Seasonal range
11.3°C
Frost days (< 0 °C)
4 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
167 d/yr
Annual snowfall
11.9 cm
Average feels-like high
14.9 °C
Average feels-like low
8.6 °C
Average peak gust
37.5 km/h
Tropical nights (≥ 20 °C)
2 d/yr
Solar radiation
13.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.9 °C
since 1940
+0.2 °C per decade · r² = 0.55 · 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
35.2 °C
15 August 2025
Coldest day
-8.4 °C
16 February 1956
Wettest day
62 mm
6 November 2011
Windiest day
58.3 km/h
29 December 1951
Strongest gust
136.1 km/h
29 December 1951
Hottest feels-like
39.5 °C
18 June 2022
Coldest feels-like
-13.5 °C
22 January 1940
Snowiest day
15.1 cm
5 January 1945
Sunniest day
14.8 h
27 June 2025
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 | 13.0 °C | +2.7 °C | 142 mm | +18 mm |
| Feb | 14.1 °C | +3.1 °C | 65 mm | -42 mm |
| Mar | 13.0 °C | +0.1 °C | 118 mm | +16 mm |
| Apr | 17.0 °C | +2.9 °C | 92 mm | -19 mm |
| May | 18.0 °C | +1.3 °C | 107 mm | +8 mm |
| Jun | 23.3 °C | +3.8 °C | 68 mm | -6 mm |
| Jul | 22.6 °C | +1.0 °C | 74 mm | +13 mm |
| Aug | 24.5 °C | +2.3 °C | 62 mm | -5 mm |
| Sep | 21.6 °C | +0.7 °C | 83 mm | -2 mm |
| Oct | 19.9 °C | +2.0 °C | 43 mm | -67 mm |
| Nov | 15.4 °C | +1.9 °C | 192 mm | +51 mm |
| Dec | 12.9 °C | +1.9 °C | 77 mm | -55 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 Ondarroa?
Ondarroa has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 13.1 °C and it receives 1,211 mm of precipitation per year.
What is the hottest day ever recorded in Ondarroa?
The hottest day measured in Ondarroa between 1940 and 2025 was 15 August 2025, reaching 35.2 °C.
What is the coldest day in Ondarroa?
The coldest day measured in Ondarroa between 1940 and 2025 was 16 February 1956, at -8.4 °C.
Does it snow in Ondarroa?
Yes. Ondarroa gets on average 11.9 cm of snow per year and has around 4 frost days.
Has the climate of Ondarroa warmed?
Yes: Ondarroa warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Ondarroa?
The wettest day measured in Ondarroa between 1940 and 2025 was 6 November 2011, with 62 mm of rain in 24 hours.
What was the windiest day in Ondarroa?
The windiest day measured in Ondarroa between 1940 and 2025 was 29 December 1951, with winds reaching 58.3 km/h.
What is the warmest month in Ondarroa?
The warmest month in Ondarroa is August (19.1 °C on average); the coldest is January (7.8 °C).
How much does it rain in Ondarroa?
Ondarroa receives on average 1,211 mm of precipitation per year, spread over about 167 rainy days.
Is it sunny in Ondarroa?
Ondarroa gets on average 9.0 hours of sunshine per day, roughly 3,285 hours per year over 1940-2025.
What is the biggest single-day snowfall in Ondarroa?
The heaviest 24-hour snowfall measured in Ondarroa between 1940 and 2025 was 5 January 1945, with 15.1 cm.
Are there tropical nights in Ondarroa?
Yes: Ondarroa has on average 2 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Ondarroa?
In Ondarroa, between 1940 and 2025, the highest apparent temperature reached 39.5 °C on 18 June 2022, and the lowest was -13.5 °C on 22 January 1940.
Compare Ondarroa with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Ondarroa