Bioul climate — normals and trends
Bioul has a temperate oceanic climate, averaging 9.4 °C annually with 817 mm of rain per year.
Climate normals · ERA5
BioulWallonia
- coords
- 50.33°, 4.80°
- period
- 1940–2025 · 86 yrs
The normals for this period
The average of every indicator across the whole window: temperature, water, sky, wind and notable days.
Mean daily temperature
9.4°C
Average daily high
12.8°C
Average daily low
5.9°C
Annual rainfall
817mm
Sunshine / day
7.3h
Mean relative humidity
81%
Average peak wind
19.7km/h
Seasonal range
15.4°C
Frost days (< 0 °C)
60 d/yr
Hot days (≥ 30 °C)
2 d/yr
Rainy days (≥ 1 mm)
154 d/yr
Annual snowfall
31.3 cm
Average feels-like high
10.3 °C
Average feels-like low
2.9 °C
Average peak gust
38.5 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
10.8 MJ/m²
Has the climate changed?
What the yearly averages say about warming here, and whether the slope is statistically solid.
+1.9 °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).
Climate month by month
How an average year unfolds: when it rains, when it turns hot, when the sun is out.
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
The most extreme days ever measured here, then the year-by-year detail.
Hottest day
36.5 °C
27 June 2026
Coldest day
-22.5 °C
22 January 1942
Wettest day
60 mm
22 June 2023
Windiest day
57.2 km/h
24 November 1984
Strongest gust
125.6 km/h
24 November 1984
Hottest feels-like
39.7 °C
27 June 2026
Coldest feels-like
-28.1 °C
22 January 1942
Snowiest day
13.3 cm
20 November 1988
Sunniest day
15.7 h
1 July 2018
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and compare it with the normal: warmer, drier, more extreme?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 4.8 °C | +0.9 °C | 169 mm | +100 mm |
| Feb | 6.4 °C | +1.2 °C | 47 mm | -16 mm |
| Mar | 12.6 °C | +3.7 °C | 15 mm | -51 mm |
| Apr | 16.5 °C | +4.0 °C | 35 mm | -27 mm |
| May | 18.6 °C | +2.2 °C | 52 mm | -22 mm |
| Jun | 23.3 °C | +3.9 °C | 80 mm | +5 mm |
| Jul | 23.0 °C | +1.8 °C | 96 mm | +21 mm |
| Aug | 23.4 °C | +2.4 °C | 49 mm | -22 mm |
| Sep | 18.6 °C | +0.6 °C | 85 mm | +26 mm |
| Oct | 13.6 °C | +0.1 °C | 77 mm | +14 mm |
| Nov | 9.6 °C | +1.7 °C | 67 mm | -2 mm |
| Dec | 7.7 °C | +2.8 °C | 29 mm | -43 mm |
The year's extremes
What was the weather like that day?
The weather actually measured on a given date, anywhere in the covered window.
Bioul (Belgium) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 9.4 °C and it receives 817 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 (17.2 °C on average) and the coldest is January (1.8 °C). Rainfall peaks in July.
Bioul averages 60 frost days, 2 hot days (≥ 30 °C) and 154 rainy days per year.
Bioul 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 77 to 43 per year over the period.
The hottest day of the period reached 36.5 °C (on 27 June 2026) and the coldest -22.5 °C (on 22 January 1942).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Frequently asked questions
What is the climate of Bioul?
Bioul has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 9.4 °C and it receives 817 mm of precipitation per year.
What is the hottest day ever recorded in Bioul?
The hottest day measured in Bioul between 1940 and 2025 was 27 June 2026, reaching 36.5 °C.
What is the coldest day in Bioul?
The coldest day measured in Bioul between 1940 and 2025 was 22 January 1942, at -22.5 °C.
Does it snow in Bioul?
Yes. Bioul gets on average 31.3 cm of snow per year and has around 60 frost days.
Has the climate of Bioul warmed?
Yes: Bioul warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Bioul?
The wettest day measured in Bioul between 1940 and 2025 was 22 June 2023, with 60 mm of rain in 24 hours.
What was the windiest day in Bioul?
The windiest day measured in Bioul between 1940 and 2025 was 24 November 1984, with winds reaching 57.2 km/h.
What is the warmest month in Bioul?
The warmest month in Bioul is July (17.2 °C on average); the coldest is January (1.8 °C).
How much does it rain in Bioul?
Bioul receives on average 817 mm of precipitation per year, spread over about 154 rainy days.
Is it sunny in Bioul?
Bioul gets on average 7.3 hours of sunshine per day, roughly 2,665 hours per year over 1940-2025.
What is the biggest single-day snowfall in Bioul?
The heaviest 24-hour snowfall measured in Bioul between 1940 and 2025 was 20 November 1988, with 13.3 cm.
Are there tropical nights in Bioul?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Bioul.
What was the most extreme apparent temperature in Bioul?
In Bioul, between 1940 and 2025, the highest apparent temperature reached 39.7 °C on 27 June 2026, and the lowest was -28.1 °C on 22 January 1942.
These forecasts and records come from our own weather API. Developer documentation →
Compare Bioul with another city
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Nearby cities
The climate around Bioul