Norrtälje climate — normals and trends
Norrtälje (Sweden) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 6.2 °C and it receives 558 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 (16.8 °C on average) and the coldest is February (-3.0 °C). Rainfall peaks in August.
Norrtälje averages 114 frost days, 0 hot days (≥ 30 °C) and 117 rainy days per year.
Norrtälje has warmed by +1.9 °C between 1940 and 2025, or +0.23 °C per decade. This trend is statistically significant.
The number of frost days there went from about 131 to 97 per year over the period.
The hottest day of the period reached 32.3 °C (on 8 August 1975) and the coldest -26.7 °C (on 10 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
NorrtäljeStockholm County
- coords
- 59.76°, 18.70°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
6.2°C
Average daily high
8.8°C
Average daily low
3.7°C
Annual rainfall
558mm
Sunshine / day
7.8h
Mean relative humidity
81%
Average peak wind
20.3km/h
Seasonal range
19.8°C
Frost days (< 0 °C)
114 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
117 d/yr
Annual snowfall
90.6 cm
Average feels-like high
5.5 °C
Average feels-like low
0.0 °C
Average peak gust
39.5 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
+1.9 °C
since 1940
+0.2 °C per decade · r² = 0.31 · 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
32.3 °C
8 August 1975
Coldest day
-26.7 °C
10 January 1987
Wettest day
55 mm
22 September 2014
Windiest day
53.7 km/h
2 November 1969
Strongest gust
112.3 km/h
2 November 1969
Hottest feels-like
32.8 °C
6 August 1975
Coldest feels-like
-33.9 °C
10 January 1987
Snowiest day
17.6 cm
21 March 1974
Sunniest day
18.0 h
23 June 1945
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 | 1.5 °C | +2.2 °C | 63 mm | +21 mm |
| Feb | 1.1 °C | +1.9 °C | 10 mm | -22 mm |
| Mar | 6.8 °C | +4.5 °C | 7 mm | -23 mm |
| Apr | 9.8 °C | +2.9 °C | 19 mm | -15 mm |
| May | 11.6 °C | -0.7 °C | 31 mm | -6 mm |
| Jun | 17.4 °C | +0.4 °C | 57 mm | +8 mm |
| Jul | 21.9 °C | +2.1 °C | 82 mm | +20 mm |
| Aug | 18.5 °C | -0.5 °C | 77 mm | +9 mm |
| Sep | 17.2 °C | +2.5 °C | 70 mm | +15 mm |
| Oct | 10.7 °C | +1.4 °C | 59 mm | +9 mm |
| Nov | 5.7 °C | +1.5 °C | 26 mm | -27 mm |
| Dec | 5.1 °C | +3.9 °C | 46 mm | -1 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 Norrtälje?
Norrtälje has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 6.2 °C and it receives 558 mm of precipitation per year.
What is the hottest day ever recorded in Norrtälje?
The hottest day measured in Norrtälje between 1940 and 2025 was 8 August 1975, reaching 32.3 °C.
What is the coldest day in Norrtälje?
The coldest day measured in Norrtälje between 1940 and 2025 was 10 January 1987, at -26.7 °C.
Does it snow in Norrtälje?
Yes. Norrtälje gets on average 90.6 cm of snow per year and has around 114 frost days.
Has the climate of Norrtälje warmed?
Yes: Norrtälje warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Norrtälje?
The wettest day measured in Norrtälje between 1940 and 2025 was 22 September 2014, with 55 mm of rain in 24 hours.
What was the windiest day in Norrtälje?
The windiest day measured in Norrtälje between 1940 and 2025 was 2 November 1969, with winds reaching 53.7 km/h.
What is the warmest month in Norrtälje?
The warmest month in Norrtälje is July (16.8 °C on average); the coldest is February (-3.0 °C).
How much does it rain in Norrtälje?
Norrtälje receives on average 558 mm of precipitation per year, spread over about 117 rainy days.
Is it sunny in Norrtälje?
Norrtälje 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 Norrtälje?
The heaviest 24-hour snowfall measured in Norrtälje between 1940 and 2025 was 21 March 1974, with 17.6 cm.
Are there tropical nights in Norrtälje?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Norrtälje.
What was the most extreme apparent temperature in Norrtälje?
In Norrtälje, between 1940 and 2025, the highest apparent temperature reached 32.8 °C on 6 August 1975, and the lowest was -33.9 °C on 10 January 1987.
Compare Norrtälje with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Norrtälje