Porsgrunn climate — normals and trends
Porsgrunn (Norway) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 5.7 °C and it receives 1,021 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 (16.1 °C on average) and the coldest is January (-4.3 °C). Rainfall peaks in August.
Porsgrunn averages 133 frost days, 0 hot days (≥ 30 °C) and 137 rainy days per year.
Porsgrunn has warmed by +2.7 °C between 1940 and 2025, or +0.32 °C per decade. This trend is statistically significant.
The number of frost days there went from about 156 to 110 per year over the period.
The hottest day of the period reached 31.4 °C (on 11 August 1975) and the coldest -26.7 °C (on 10 February 1985).
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
PorsgrunnTelemark
- coords
- 59.14°, 9.66°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
5.7°C
Average daily high
9.0°C
Average daily low
2.4°C
Annual rainfall
1,021mm
Sunshine / day
8.0h
Mean relative humidity
78%
Average peak wind
14.9km/h
Seasonal range
20.4°C
Frost days (< 0 °C)
133 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
137 d/yr
Annual snowfall
194.9 cm
Average feels-like high
6.2 °C
Average feels-like low
-0.8 °C
Average peak gust
35.7 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
+2.7 °C
since 1940
+0.3 °C per decade · r² = 0.43 · 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
31.4 °C
11 August 1975
Coldest day
-26.7 °C
10 February 1985
Wettest day
64 mm
2 September 2015
Windiest day
41.3 km/h
4 October 2025
Strongest gust
109.1 km/h
15 September 1994
Hottest feels-like
31.9 °C
11 August 1975
Coldest feels-like
-32.6 °C
26 January 1942
Snowiest day
32.6 cm
6 November 1971
Sunniest day
17.6 h
20 June 2017
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 | 0.0 °C | +2.0 °C | 125 mm | +43 mm |
| Feb | 1.6 °C | +2.3 °C | 45 mm | -17 mm |
| Mar | 7.7 °C | +4.2 °C | 27 mm | -34 mm |
| Apr | 12.6 °C | +4.2 °C | 46 mm | -11 mm |
| May | 15.9 °C | +1.7 °C | 38 mm | -34 mm |
| Jun | 18.4 °C | +0.3 °C | 55 mm | -27 mm |
| Jul | 23.6 °C | +3.6 °C | 130 mm | +31 mm |
| Aug | 19.7 °C | +0.7 °C | 99 mm | -10 mm |
| Sep | 16.1 °C | +1.2 °C | 185 mm | +84 mm |
| Oct | 10.9 °C | +1.5 °C | 168 mm | +63 mm |
| Nov | 5.8 °C | +2.2 °C | 97 mm | -9 mm |
| Dec | 3.9 °C | +3.9 °C | 130 mm | +46 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 Porsgrunn?
Porsgrunn has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 5.7 °C and it receives 1,021 mm of precipitation per year.
What is the hottest day ever recorded in Porsgrunn?
The hottest day measured in Porsgrunn between 1940 and 2025 was 11 August 1975, reaching 31.4 °C.
What is the coldest day in Porsgrunn?
The coldest day measured in Porsgrunn between 1940 and 2025 was 10 February 1985, at -26.7 °C.
Does it snow in Porsgrunn?
Yes. Porsgrunn gets on average 194.9 cm of snow per year and has around 133 frost days.
Has the climate of Porsgrunn warmed?
Yes: Porsgrunn warmed by +2.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Porsgrunn?
The wettest day measured in Porsgrunn between 1940 and 2025 was 2 September 2015, with 64 mm of rain in 24 hours.
What was the windiest day in Porsgrunn?
The windiest day measured in Porsgrunn between 1940 and 2025 was 4 October 2025, with winds reaching 41.3 km/h.
What is the warmest month in Porsgrunn?
The warmest month in Porsgrunn is July (16.1 °C on average); the coldest is January (-4.3 °C).
How much does it rain in Porsgrunn?
Porsgrunn receives on average 1,021 mm of precipitation per year, spread over about 137 rainy days.
Is it sunny in Porsgrunn?
Porsgrunn gets on average 8.0 hours of sunshine per day, roughly 2,920 hours per year over 1940-2025.
What is the biggest single-day snowfall in Porsgrunn?
The heaviest 24-hour snowfall measured in Porsgrunn between 1940 and 2025 was 6 November 1971, with 32.6 cm.
Are there tropical nights in Porsgrunn?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Porsgrunn.
What was the most extreme apparent temperature in Porsgrunn?
In Porsgrunn, between 1940 and 2025, the highest apparent temperature reached 31.9 °C on 11 August 1975, and the lowest was -32.6 °C on 26 January 1942.
Compare Porsgrunn with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Porsgrunn