Perniö climate — normals and trends
Perniö (Finland) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 5.2 °C and it receives 680 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 (17.0 °C on average) and the coldest is February (-5.6 °C). Rainfall peaks in August.
Perniö averages 144 frost days, 0 hot days (≥ 30 °C) and 130 rainy days per year.
Perniö 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 162 to 126 per year over the period.
The hottest day of the period reached 32.0 °C (on 28 July 2019) and the coldest -36.8 °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
PerniöSouthwest Finland
- coords
- 60.20°, 23.13°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
5.2°C
Average daily high
8.2°C
Average daily low
1.9°C
Annual rainfall
680mm
Sunshine / day
7.6h
Mean relative humidity
81%
Average peak wind
18.2km/h
Seasonal range
22.6°C
Frost days (< 0 °C)
144 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
130 d/yr
Annual snowfall
119.0 cm
Average feels-like high
5.0 °C
Average feels-like low
-1.6 °C
Average peak gust
36.5 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
9.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.4 °C
since 1940
+0.3 °C per decade · r² = 0.38 · 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
32.0 °C
28 July 2019
Coldest day
-36.8 °C
10 January 1987
Wettest day
51 mm
12 August 1972
Windiest day
48.8 km/h
23 January 1995
Strongest gust
103.7 km/h
23 January 1995
Hottest feels-like
33.2 °C
14 July 2021
Coldest feels-like
-43.4 °C
10 January 1987
Snowiest day
17.3 cm
7 November 1941
Sunniest day
17.8 h
26 June 2025
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 | 1.3 °C | +4.2 °C | 64 mm | +12 mm |
| Feb | 0.1 °C | +3.3 °C | 23 mm | -17 mm |
| Mar | 5.6 °C | +5.0 °C | 11 mm | -26 mm |
| Apr | 9.4 °C | +2.6 °C | 50 mm | +11 mm |
| May | 12.9 °C | -0.6 °C | 39 mm | -3 mm |
| Jun | 17.1 °C | -1.2 °C | 97 mm | +41 mm |
| Jul | 23.5 °C | +2.8 °C | 97 mm | +17 mm |
| Aug | 19.0 °C | -0.4 °C | 71 mm | -17 mm |
| Sep | 17.1 °C | +2.8 °C | 85 mm | +20 mm |
| Oct | 9.6 °C | +1.3 °C | 58 mm | -1 mm |
| Nov | 6.0 °C | +3.1 °C | 51 mm | -11 mm |
| Dec | 4.1 °C | +4.5 °C | 55 mm | -4 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 Perniö?
Perniö has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 5.2 °C and it receives 680 mm of precipitation per year.
What is the hottest day ever recorded in Perniö?
The hottest day measured in Perniö between 1940 and 2025 was 28 July 2019, reaching 32.0 °C.
What is the coldest day in Perniö?
The coldest day measured in Perniö between 1940 and 2025 was 10 January 1987, at -36.8 °C.
Does it snow in Perniö?
Yes. Perniö gets on average 119.0 cm of snow per year and has around 144 frost days.
Has the climate of Perniö warmed?
Yes: Perniö warmed by +2.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Perniö?
The wettest day measured in Perniö between 1940 and 2025 was 12 August 1972, with 51 mm of rain in 24 hours.
What was the windiest day in Perniö?
The windiest day measured in Perniö between 1940 and 2025 was 23 January 1995, with winds reaching 48.8 km/h.
What is the warmest month in Perniö?
The warmest month in Perniö is July (17.0 °C on average); the coldest is February (-5.6 °C).
How much does it rain in Perniö?
Perniö receives on average 680 mm of precipitation per year, spread over about 130 rainy days.
Is it sunny in Perniö?
Perniö gets on average 7.6 hours of sunshine per day, roughly 2,774 hours per year over 1940-2025.
What is the biggest single-day snowfall in Perniö?
The heaviest 24-hour snowfall measured in Perniö between 1940 and 2025 was 7 November 1941, with 17.3 cm.
Are there tropical nights in Perniö?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Perniö.
What was the most extreme apparent temperature in Perniö?
In Perniö, between 1940 and 2025, the highest apparent temperature reached 33.2 °C on 14 July 2021, and the lowest was -43.4 °C on 10 January 1987.
Compare Perniö with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Perniö