Järna climate — normals and trends
Järna (Sweden) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 6.6 °C and it receives 588 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 (17.3 °C on average) and the coldest is February (-2.9 °C). Rainfall peaks in August.
Järna averages 119 frost days, 0 hot days (≥ 30 °C) and 120 rainy days per year.
Järna has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The number of frost days there went from about 133 to 105 per year over the period.
The hottest day of the period reached 34.1 °C (on 7 August 1975) and the coldest -27.9 °C (on 18 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
JärnaStockholm County
- coords
- 59.09°, 17.57°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
6.6°C
Average daily high
9.6°C
Average daily low
3.4°C
Annual rainfall
588mm
Sunshine / day
7.8h
Mean relative humidity
79%
Average peak wind
17.7km/h
Seasonal range
20.2°C
Frost days (< 0 °C)
119 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
120 d/yr
Annual snowfall
81.4 cm
Average feels-like high
6.6 °C
Average feels-like low
0.0 °C
Average peak gust
37.8 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
10.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.26 · 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
7 August 1975
Coldest day
-27.9 °C
18 January 1940
Wettest day
48 mm
31 August 2012
Windiest day
48.1 km/h
2 November 1969
Strongest gust
108.0 km/h
13 January 1984
Hottest feels-like
33.6 °C
7 August 1975
Coldest feels-like
-33.8 °C
10 January 1987
Snowiest day
18.7 cm
6 December 1985
Sunniest day
17.9 h
26 June 2020
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 | 2.1 °C | +2.8 °C | 64 mm | +23 mm |
| Feb | 1.6 °C | +2.0 °C | 8 mm | -25 mm |
| Mar | 7.7 °C | +4.5 °C | 7 mm | -24 mm |
| Apr | 11.9 °C | +3.5 °C | 15 mm | -22 mm |
| May | 13.8 °C | -0.4 °C | 37 mm | -6 mm |
| Jun | 19.3 °C | +0.4 °C | 63 mm | +5 mm |
| Jul | 23.4 °C | +2.3 °C | 97 mm | +24 mm |
| Aug | 19.7 °C | -0.3 °C | 57 mm | -17 mm |
| Sep | 17.9 °C | +2.4 °C | 74 mm | +19 mm |
| Oct | 11.1 °C | +1.2 °C | 53 mm | +5 mm |
| Nov | 5.5 °C | +1.2 °C | 37 mm | -13 mm |
| Dec | 4.9 °C | +3.7 °C | 38 mm | -9 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 Järna?
Järna has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 6.6 °C and it receives 588 mm of precipitation per year.
What is the hottest day ever recorded in Järna?
The hottest day measured in Järna between 1940 and 2025 was 7 August 1975, reaching 34.1 °C.
What is the coldest day in Järna?
The coldest day measured in Järna between 1940 and 2025 was 18 January 1940, at -27.9 °C.
Does it snow in Järna?
Yes. Järna gets on average 81.4 cm of snow per year and has around 119 frost days.
Has the climate of Järna warmed?
Yes: Järna warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Järna?
The wettest day measured in Järna between 1940 and 2025 was 31 August 2012, with 48 mm of rain in 24 hours.
What was the windiest day in Järna?
The windiest day measured in Järna between 1940 and 2025 was 2 November 1969, with winds reaching 48.1 km/h.
What is the warmest month in Järna?
The warmest month in Järna is July (17.3 °C on average); the coldest is February (-2.9 °C).
How much does it rain in Järna?
Järna receives on average 588 mm of precipitation per year, spread over about 120 rainy days.
Is it sunny in Järna?
Järna 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 Järna?
The heaviest 24-hour snowfall measured in Järna between 1940 and 2025 was 6 December 1985, with 18.7 cm.
Are there tropical nights in Järna?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Järna.
What was the most extreme apparent temperature in Järna?
In Järna, between 1940 and 2025, the highest apparent temperature reached 33.6 °C on 7 August 1975, and the lowest was -33.8 °C on 10 January 1987.
Compare Järna with another city
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Nearby cities
The climate around Järna