Bolsward climate — normals and trends
Bolsward (The Netherlands) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 10.0 °C and it receives 937 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 (17.2 °C on average) and the coldest is February (3.3 °C). Rainfall peaks in August.
Bolsward averages 22 frost days, 0 hot days (≥ 30 °C) and 161 rainy days per year.
Bolsward has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The number of frost days there went from about 33 to 11 per year over the period.
The hottest day of the period reached 29.5 °C (on 25 July 2019) and the coldest -12.4 °C (on 22 January 1940).
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
BolswardFriesland
- coords
- 53.07°, 5.53°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.0°C
Average daily high
11.4°C
Average daily low
8.7°C
Annual rainfall
937mm
Sunshine / day
8.0h
Mean relative humidity
81%
Average peak wind
31.7km/h
Seasonal range
13.9°C
Frost days (< 0 °C)
22 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
161 d/yr
Annual snowfall
16.3 cm
Average feels-like high
8.0 °C
Average feels-like low
4.1 °C
Average peak gust
45.1 km/h
Tropical nights (≥ 20 °C)
1 d/yr
Solar radiation
10.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.42 · 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
29.5 °C
25 July 2019
Coldest day
-12.4 °C
22 January 1940
Wettest day
50 mm
15 September 1994
Windiest day
88.2 km/h
13 November 1972
Strongest gust
141.8 km/h
25 January 1990
Hottest feels-like
33.0 °C
25 July 2019
Coldest feels-like
-22.4 °C
14 January 1987
Snowiest day
14.8 cm
25 February 1958
Sunniest day
16.2 h
21 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 | 5.4 °C | +0.7 °C | 72 mm | -2 mm |
| Feb | 4.7 °C | +0.1 °C | 34 mm | -22 mm |
| Mar | 8.8 °C | +2.2 °C | 11 mm | -46 mm |
| Apr | 12.4 °C | +2.9 °C | 23 mm | -25 mm |
| May | 14.9 °C | +1.8 °C | 54 mm | -4 mm |
| Jun | 18.8 °C | +2.8 °C | 87 mm | +20 mm |
| Jul | 20.1 °C | +2.0 °C | 104 mm | +13 mm |
| Aug | 19.8 °C | +1.1 °C | 53 mm | -48 mm |
| Sep | 17.6 °C | +0.9 °C | 118 mm | +21 mm |
| Oct | 13.5 °C | +0.2 °C | 142 mm | +45 mm |
| Nov | 9.5 °C | +0.3 °C | 107 mm | +7 mm |
| Dec | 7.4 °C | +1.0 °C | 32 mm | -57 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 Bolsward?
Bolsward has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 10.0 °C and it receives 937 mm of precipitation per year.
What is the hottest day ever recorded in Bolsward?
The hottest day measured in Bolsward between 1940 and 2025 was 25 July 2019, reaching 29.5 °C.
What is the coldest day in Bolsward?
The coldest day measured in Bolsward between 1940 and 2025 was 22 January 1940, at -12.4 °C.
Does it snow in Bolsward?
Yes. Bolsward gets on average 16.3 cm of snow per year and has around 22 frost days.
Has the climate of Bolsward warmed?
Yes: Bolsward warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Bolsward?
The wettest day measured in Bolsward between 1940 and 2025 was 15 September 1994, with 50 mm of rain in 24 hours.
What was the windiest day in Bolsward?
The windiest day measured in Bolsward between 1940 and 2025 was 13 November 1972, with winds reaching 88.2 km/h.
What is the warmest month in Bolsward?
The warmest month in Bolsward is August (17.2 °C on average); the coldest is February (3.3 °C).
How much does it rain in Bolsward?
Bolsward receives on average 937 mm of precipitation per year, spread over about 161 rainy days.
Is it sunny in Bolsward?
Bolsward gets on average 8.0 hours of sunshine per day, roughly 2,920 hours per year over 1940-2025.
What is the biggest single-day snowfall in Bolsward?
The heaviest 24-hour snowfall measured in Bolsward between 1940 and 2025 was 25 February 1958, with 14.8 cm.
Are there tropical nights in Bolsward?
Yes: Bolsward has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Bolsward?
In Bolsward, between 1940 and 2025, the highest apparent temperature reached 33.0 °C on 25 July 2019, and the lowest was -22.4 °C on 14 January 1987.
Compare Bolsward with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Bolsward