Jämsänkoski climate — normals and trends
Jämsänkoski (Finland) has a subarctic climate (Dfc) under the Köppen-Geiger classification. Its mean annual temperature is 3.7 °C and it receives 657 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 (-8.3 °C). Rainfall peaks in August.
Jämsänkoski averages 169 frost days, 1 hot days (≥ 30 °C) and 133 rainy days per year.
Jämsänkoski has warmed by +2.3 °C between 1940 and 2025, or +0.27 °C per decade. This trend is statistically significant.
The number of frost days there went from about 182 to 156 per year over the period.
The hottest day of the period reached 34.1 °C (on 29 July 2010) and the coldest -37.7 °C (on 8 January 1987).
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
JämsänkoskiCentral Finland
- coords
- 61.92°, 25.17°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
3.7°C
Average daily high
7.0°C
Average daily low
0.3°C
Annual rainfall
657mm
Sunshine / day
6.6h
Mean relative humidity
81%
Average peak wind
15.9km/h
Seasonal range
25.0°C
Frost days (< 0 °C)
169 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
133 d/yr
Annual snowfall
141.8 cm
Average feels-like high
3.8 °C
Average feels-like low
-3.2 °C
Average peak gust
35.2 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
8.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.3 °C
since 1940
+0.3 °C per decade · r² = 0.32 · 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
34.1 °C
29 July 2010
Coldest day
-37.7 °C
8 January 1987
Wettest day
63 mm
8 August 1943
Windiest day
41.8 km/h
23 January 1995
Strongest gust
92.9 km/h
23 November 2008
Hottest feels-like
34.7 °C
8 August 2010
Coldest feels-like
-42.9 °C
8 January 1987
Snowiest day
21.9 cm
25 January 2002
Sunniest day
18.9 h
16 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
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Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | -1.4 °C | +4.4 °C | 50 mm | +10 mm |
| Feb | -2.2 °C | +3.2 °C | 20 mm | -11 mm |
| Mar | 4.2 °C | +4.5 °C | 41 mm | +8 mm |
| Apr | 9.4 °C | +3.3 °C | 51 mm | +11 mm |
| May | 13.0 °C | -0.9 °C | 44 mm | -3 mm |
| Jun | 17.8 °C | -0.9 °C | 110 mm | +43 mm |
| Jul | 25.2 °C | +4.4 °C | 61 mm | -23 mm |
| Aug | 19.1 °C | +0.3 °C | 85 mm | -3 mm |
| Sep | 16.5 °C | +3.5 °C | 80 mm | +17 mm |
| Oct | 8.1 °C | +1.6 °C | 57 mm | -3 mm |
| Nov | 3.9 °C | +3.2 °C | 53 mm | -1 mm |
| Dec | 1.6 °C | +4.8 °C | 72 mm | +23 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 Jämsänkoski?
Jämsänkoski has a subarctic climate (Köppen Dfc). Over 1940-2025, the average annual temperature is 3.7 °C and it receives 657 mm of precipitation per year.
What is the hottest day ever recorded in Jämsänkoski?
The hottest day measured in Jämsänkoski between 1940 and 2025 was 29 July 2010, reaching 34.1 °C.
What is the coldest day in Jämsänkoski?
The coldest day measured in Jämsänkoski between 1940 and 2025 was 8 January 1987, at -37.7 °C.
Does it snow in Jämsänkoski?
Yes. Jämsänkoski gets on average 141.8 cm of snow per year and has around 169 frost days.
Has the climate of Jämsänkoski warmed?
Yes: Jämsänkoski warmed by +2.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Jämsänkoski?
The wettest day measured in Jämsänkoski between 1940 and 2025 was 8 August 1943, with 63 mm of rain in 24 hours.
What was the windiest day in Jämsänkoski?
The windiest day measured in Jämsänkoski between 1940 and 2025 was 23 January 1995, with winds reaching 41.8 km/h.
What is the warmest month in Jämsänkoski?
The warmest month in Jämsänkoski is July (16.7 °C on average); the coldest is January (-8.3 °C).
How much does it rain in Jämsänkoski?
Jämsänkoski receives on average 657 mm of precipitation per year, spread over about 133 rainy days.
Is it sunny in Jämsänkoski?
Jämsänkoski gets on average 6.6 hours of sunshine per day, roughly 2,409 hours per year over 1940-2025.
What is the biggest single-day snowfall in Jämsänkoski?
The heaviest 24-hour snowfall measured in Jämsänkoski between 1940 and 2025 was 25 January 2002, with 21.9 cm.
Are there tropical nights in Jämsänkoski?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Jämsänkoski.
What was the most extreme apparent temperature in Jämsänkoski?
In Jämsänkoski, between 1940 and 2025, the highest apparent temperature reached 34.7 °C on 8 August 2010, and the lowest was -42.9 °C on 8 January 1987.
Compare Jämsänkoski with another city
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Nearby cities
The climate around Jämsänkoski