Sastamala climate — normals and trends
Sastamala (Finland) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 4.5 °C and it receives 646 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 (16.7 °C on average) and the coldest is January (-6.6 °C). Rainfall peaks in July.
Sastamala averages 158 frost days, 1 hot days (≥ 30 °C) and 129 rainy days per year.
Sastamala has warmed by +2.4 °C between 1940 and 2025, or +0.28 °C per decade. This trend is statistically significant.
The number of frost days there went from about 176 to 140 per year over the period.
The hottest day of the period reached 32.2 °C (on 13 July 2010) and the coldest -37.4 °C (on 3 February 1966).
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
SastamalaPirkanmaa
- coords
- 61.35°, 22.91°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
4.5°C
Average daily high
7.9°C
Average daily low
1.0°C
Annual rainfall
646mm
Sunshine / day
7.1h
Mean relative humidity
81%
Average peak wind
15.7km/h
Seasonal range
23.3°C
Frost days (< 0 °C)
158 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
129 d/yr
Annual snowfall
116.7 cm
Average feels-like high
4.8 °C
Average feels-like low
-2.4 °C
Average peak gust
35.2 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
9.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.4 °C
since 1940
+0.3 °C per decade · r² = 0.36 · 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
32.2 °C
13 July 2010
Coldest day
-37.4 °C
3 February 1966
Wettest day
50 mm
28 August 2023
Windiest day
41.9 km/h
29 March 1989
Strongest gust
96.5 km/h
14 January 1984
Hottest feels-like
33.1 °C
8 August 2010
Coldest feels-like
-42.4 °C
3 February 1966
Snowiest day
18.1 cm
18 April 1972
Sunniest day
19.0 h
21 June 2012
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 | 0.4 °C | +4.5 °C | 53 mm | +12 mm |
| Feb | -0.3 °C | +3.5 °C | 16 mm | -16 mm |
| Mar | 5.8 °C | +4.9 °C | 20 mm | -13 mm |
| Apr | 9.8 °C | +2.4 °C | 48 mm | +8 mm |
| May | 13.1 °C | -1.3 °C | 47 mm | -1 mm |
| Jun | 17.8 °C | -1.1 °C | 78 mm | +11 mm |
| Jul | 24.6 °C | +3.7 °C | 85 mm | -1 mm |
| Aug | 18.8 °C | -0.5 °C | 92 mm | +6 mm |
| Sep | 17.1 °C | +3.2 °C | 78 mm | +18 mm |
| Oct | 8.9 °C | +1.4 °C | 57 mm | +3 mm |
| Nov | 4.9 °C | +3.2 °C | 57 mm | +5 mm |
| Dec | 3.4 °C | +5.1 °C | 62 mm | +14 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 Sastamala?
Sastamala has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 4.5 °C and it receives 646 mm of precipitation per year.
What is the hottest day ever recorded in Sastamala?
The hottest day measured in Sastamala between 1940 and 2025 was 13 July 2010, reaching 32.2 °C.
What is the coldest day in Sastamala?
The coldest day measured in Sastamala between 1940 and 2025 was 3 February 1966, at -37.4 °C.
Does it snow in Sastamala?
Yes. Sastamala gets on average 116.7 cm of snow per year and has around 158 frost days.
Has the climate of Sastamala warmed?
Yes: Sastamala warmed by +2.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Sastamala?
The wettest day measured in Sastamala between 1940 and 2025 was 28 August 2023, with 50 mm of rain in 24 hours.
What was the windiest day in Sastamala?
The windiest day measured in Sastamala between 1940 and 2025 was 29 March 1989, with winds reaching 41.9 km/h.
What is the warmest month in Sastamala?
The warmest month in Sastamala is July (16.7 °C on average); the coldest is January (-6.6 °C).
How much does it rain in Sastamala?
Sastamala receives on average 646 mm of precipitation per year, spread over about 129 rainy days.
Is it sunny in Sastamala?
Sastamala gets on average 7.1 hours of sunshine per day, roughly 2,592 hours per year over 1940-2025.
What is the biggest single-day snowfall in Sastamala?
The heaviest 24-hour snowfall measured in Sastamala between 1940 and 2025 was 18 April 1972, with 18.1 cm.
Are there tropical nights in Sastamala?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Sastamala.
What was the most extreme apparent temperature in Sastamala?
In Sastamala, between 1940 and 2025, the highest apparent temperature reached 33.1 °C on 8 August 2010, and the lowest was -42.4 °C on 3 February 1966.
Compare Sastamala with another city
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Nearby cities
The climate around Sastamala