Zwoleń climate — normals and trends
Zwoleń (Poland) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 8.4 °C and it receives 658 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 (18.8 °C on average) and the coldest is January (-2.7 °C). Rainfall peaks in July.
Zwoleń averages 99 frost days, 4 hot days (≥ 30 °C) and 132 rainy days per year.
Zwoleń has warmed by +2.5 °C between 1940 and 2025, or +0.29 °C per decade. This trend is statistically significant.
The number of frost days there went from about 119 to 79 per year over the period.
The hottest day of the period reached 35.7 °C (on 8 August 2013) and the coldest -32.2 °C (on 11 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
ZwoleńMazovia
- coords
- 51.36°, 21.59°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
8.4°C
Average daily high
12.1°C
Average daily low
4.7°C
Annual rainfall
658mm
Sunshine / day
7.4h
Mean relative humidity
78%
Average peak wind
16.9km/h
Seasonal range
21.5°C
Frost days (< 0 °C)
99 d/yr
Hot days (≥ 30 °C)
4 d/yr
Rainy days (≥ 1 mm)
132 d/yr
Annual snowfall
63.3 cm
Average feels-like high
9.6 °C
Average feels-like low
1.7 °C
Average peak gust
34.7 km/h
Tropical nights (≥ 20 °C)
1 d/yr
Solar radiation
10.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.5 °C
since 1940
+0.3 °C per decade · r² = 0.48 · 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
35.7 °C
8 August 2013
Coldest day
-32.2 °C
11 January 1940
Wettest day
65 mm
12 August 1949
Windiest day
50.4 km/h
20 January 1986
Strongest gust
113.8 km/h
20 January 1986
Hottest feels-like
37.4 °C
29 July 2005
Coldest feels-like
-37.4 °C
11 January 1940
Snowiest day
21.1 cm
30 January 1979
Sunniest day
15.4 h
24 June 2008
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 | 5.0 °C | +5.3 °C | 44 mm | +5 mm |
| Feb | 2.6 °C | +1.2 °C | 22 mm | -16 mm |
| Mar | 11.9 °C | +5.8 °C | 47 mm | +7 mm |
| Apr | 16.4 °C | +3.5 °C | 33 mm | -18 mm |
| May | 16.0 °C | -2.3 °C | 73 mm | +5 mm |
| Jun | 23.2 °C | +1.5 °C | 77 mm | -2 mm |
| Jul | 24.4 °C | +1.0 °C | 118 mm | +32 mm |
| Aug | 24.6 °C | +1.5 °C | 29 mm | -42 mm |
| Sep | 20.5 °C | +2.1 °C | 80 mm | +23 mm |
| Oct | 12.1 °C | -0.5 °C | 58 mm | +14 mm |
| Nov | 7.0 °C | +1.0 °C | 65 mm | +21 mm |
| Dec | 3.9 °C | +2.2 °C | 21 mm | -21 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 Zwoleń?
Zwoleń has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 8.4 °C and it receives 658 mm of precipitation per year.
What is the hottest day ever recorded in Zwoleń?
The hottest day measured in Zwoleń between 1940 and 2025 was 8 August 2013, reaching 35.7 °C.
What is the coldest day in Zwoleń?
The coldest day measured in Zwoleń between 1940 and 2025 was 11 January 1940, at -32.2 °C.
Does it snow in Zwoleń?
Yes. Zwoleń gets on average 63.3 cm of snow per year and has around 99 frost days.
Has the climate of Zwoleń warmed?
Yes: Zwoleń warmed by +2.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Zwoleń?
The wettest day measured in Zwoleń between 1940 and 2025 was 12 August 1949, with 65 mm of rain in 24 hours.
What was the windiest day in Zwoleń?
The windiest day measured in Zwoleń between 1940 and 2025 was 20 January 1986, with winds reaching 50.4 km/h.
What is the warmest month in Zwoleń?
The warmest month in Zwoleń is July (18.8 °C on average); the coldest is January (-2.7 °C).
How much does it rain in Zwoleń?
Zwoleń receives on average 658 mm of precipitation per year, spread over about 132 rainy days.
Is it sunny in Zwoleń?
Zwoleń gets on average 7.4 hours of sunshine per day, roughly 2,701 hours per year over 1940-2025.
What is the biggest single-day snowfall in Zwoleń?
The heaviest 24-hour snowfall measured in Zwoleń between 1940 and 2025 was 30 January 1979, with 21.1 cm.
Are there tropical nights in Zwoleń?
Yes: Zwoleń has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Zwoleń?
In Zwoleń, between 1940 and 2025, the highest apparent temperature reached 37.4 °C on 29 July 2005, and the lowest was -37.4 °C on 11 January 1940.
Compare Zwoleń with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Zwoleń