Semily climate — normals and trends
Semily (Czechia) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 8.0 °C and it receives 696 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 (17.8 °C on average) and the coldest is January (-2.3 °C). Rainfall peaks in July.
Semily averages 104 frost days, 3 hot days (≥ 30 °C) and 137 rainy days per year.
Semily 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 124 to 84 per year over the period.
The hottest day of the period reached 36.2 °C (on 20 August 2012) and the coldest -27.3 °C (on 9 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
SemilyLiberec Region
- coords
- 50.60°, 15.34°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
8.0°C
Average daily high
11.6°C
Average daily low
4.5°C
Annual rainfall
696mm
Sunshine / day
7.8h
Mean relative humidity
78%
Average peak wind
15.1km/h
Seasonal range
20.1°C
Frost days (< 0 °C)
104 d/yr
Hot days (≥ 30 °C)
3 d/yr
Rainy days (≥ 1 mm)
137 d/yr
Annual snowfall
78.8 cm
Average feels-like high
9.2 °C
Average feels-like low
1.8 °C
Average peak gust
33.4 km/h
Tropical nights (≥ 20 °C)
1 d/yr
Solar radiation
10.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.5 °C
since 1940
+0.3 °C per decade · r² = 0.51 · 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
36.2 °C
20 August 2012
Coldest day
-27.3 °C
9 February 1956
Wettest day
54 mm
18 August 2015
Windiest day
44.0 km/h
17 February 1962
Strongest gust
115.6 km/h
29 October 2017
Hottest feels-like
37.9 °C
22 August 1943
Coldest feels-like
-32.8 °C
9 February 1956
Snowiest day
12.9 cm
26 November 1969
Sunniest day
16.0 h
18 June 2000
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 | 2.8 °C | +2.8 °C | 62 mm | +8 mm |
| Feb | 2.9 °C | +1.0 °C | 12 mm | -36 mm |
| Mar | 10.8 °C | +4.3 °C | 30 mm | -21 mm |
| Apr | 15.7 °C | +3.5 °C | 34 mm | -13 mm |
| May | 17.0 °C | -0.1 °C | 51 mm | -13 mm |
| Jun | 24.0 °C | +3.5 °C | 59 mm | -11 mm |
| Jul | 23.7 °C | +1.4 °C | 80 mm | +4 mm |
| Aug | 24.4 °C | +2.1 °C | 67 mm | +0 mm |
| Sep | 19.4 °C | +1.5 °C | 83 mm | +29 mm |
| Oct | 11.3 °C | -0.7 °C | 61 mm | +12 mm |
| Nov | 5.9 °C | +0.5 °C | 48 mm | -8 mm |
| Dec | 3.3 °C | +1.8 °C | 30 mm | -29 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 Semily?
Semily has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 8.0 °C and it receives 696 mm of precipitation per year.
What is the hottest day ever recorded in Semily?
The hottest day measured in Semily between 1940 and 2025 was 20 August 2012, reaching 36.2 °C.
What is the coldest day in Semily?
The coldest day measured in Semily between 1940 and 2025 was 9 February 1956, at -27.3 °C.
Does it snow in Semily?
Yes. Semily gets on average 78.8 cm of snow per year and has around 104 frost days.
Has the climate of Semily warmed?
Yes: Semily warmed by +2.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Semily?
The wettest day measured in Semily between 1940 and 2025 was 18 August 2015, with 54 mm of rain in 24 hours.
What was the windiest day in Semily?
The windiest day measured in Semily between 1940 and 2025 was 17 February 1962, with winds reaching 44.0 km/h.
What is the warmest month in Semily?
The warmest month in Semily is July (17.8 °C on average); the coldest is January (-2.3 °C).
How much does it rain in Semily?
Semily receives on average 696 mm of precipitation per year, spread over about 137 rainy days.
Is it sunny in Semily?
Semily gets on average 7.8 hours of sunshine per day, roughly 2,847 hours per year over 1940-2025.
What is the biggest single-day snowfall in Semily?
The heaviest 24-hour snowfall measured in Semily between 1940 and 2025 was 26 November 1969, with 12.9 cm.
Are there tropical nights in Semily?
Yes: Semily has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Semily?
In Semily, between 1940 and 2025, the highest apparent temperature reached 37.9 °C on 22 August 1943, and the lowest was -32.8 °C on 9 February 1956.
Compare Semily with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Semily