Porvoo climate — normals and trends
Porvoo (Finland) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 5.1 °C and it receives 642 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 (17.6 °C on average) and the coldest is January (-6.3 °C). Rainfall peaks in August.
Porvoo averages 149 frost days, 1 hot days (≥ 30 °C) and 130 rainy days per year.
Porvoo has warmed by +2.4 °C between 1940 and 2025, or +0.29 °C per decade. This trend is statistically significant.
The number of frost days there went from about 168 to 130 per year over the period.
The hottest day of the period reached 32.8 °C (on 29 July 1994) 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
PorvooUusimaa
- coords
- 60.39°, 25.67°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
5.1°C
Average daily high
8.4°C
Average daily low
1.6°C
Annual rainfall
642mm
Sunshine / day
7.4h
Mean relative humidity
79%
Average peak wind
16.7km/h
Seasonal range
23.9°C
Frost days (< 0 °C)
149 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
130 d/yr
Annual snowfall
132.3 cm
Average feels-like high
5.2 °C
Average feels-like low
-1.9 °C
Average peak gust
36.8 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
9.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.4 °C
since 1940
+0.3 °C per decade · r² = 0.37 · 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
32.8 °C
29 July 1994
Coldest day
-36.8 °C
10 January 1987
Wettest day
61 mm
12 August 1972
Windiest day
43.9 km/h
23 January 1995
Strongest gust
96.5 km/h
23 January 1995
Hottest feels-like
33.8 °C
29 July 1994
Coldest feels-like
-43.2 °C
10 January 1987
Snowiest day
16.8 cm
20 December 1970
Sunniest day
18.1 h
16 June 2015
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 | 1.1 °C | +5.0 °C | 71 mm | +23 mm |
| Feb | -1.1 °C | +2.5 °C | 12 mm | -27 mm |
| Mar | 5.9 °C | +5.0 °C | 16 mm | -22 mm |
| Apr | 10.2 °C | +2.6 °C | 36 mm | -4 mm |
| May | 14.1 °C | -0.7 °C | 39 mm | -5 mm |
| Jun | 18.2 °C | -1.3 °C | 136 mm | +76 mm |
| Jul | 24.7 °C | +3.0 °C | 105 mm | +31 mm |
| Aug | 19.6 °C | -0.5 °C | 87 mm | +11 mm |
| Sep | 17.5 °C | +3.0 °C | 63 mm | +5 mm |
| Oct | 9.4 °C | +1.3 °C | 57 mm | +3 mm |
| Nov | 5.5 °C | +3.2 °C | 33 mm | -24 mm |
| Dec | 3.2 °C | +4.5 °C | 51 mm | -5 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 Porvoo?
Porvoo has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 5.1 °C and it receives 642 mm of precipitation per year.
What is the hottest day ever recorded in Porvoo?
The hottest day measured in Porvoo between 1940 and 2025 was 29 July 1994, reaching 32.8 °C.
What is the coldest day in Porvoo?
The coldest day measured in Porvoo between 1940 and 2025 was 10 January 1987, at -36.8 °C.
Does it snow in Porvoo?
Yes. Porvoo gets on average 132.3 cm of snow per year and has around 149 frost days.
Has the climate of Porvoo warmed?
Yes: Porvoo warmed by +2.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Porvoo?
The wettest day measured in Porvoo between 1940 and 2025 was 12 August 1972, with 61 mm of rain in 24 hours.
What was the windiest day in Porvoo?
The windiest day measured in Porvoo between 1940 and 2025 was 23 January 1995, with winds reaching 43.9 km/h.
What is the warmest month in Porvoo?
The warmest month in Porvoo is July (17.6 °C on average); the coldest is January (-6.3 °C).
How much does it rain in Porvoo?
Porvoo receives on average 642 mm of precipitation per year, spread over about 130 rainy days.
Is it sunny in Porvoo?
Porvoo gets on average 7.4 hours of sunshine per day, roughly 2,701 hours per year over 1940-2025.
What is the biggest single-day snowfall in Porvoo?
The heaviest 24-hour snowfall measured in Porvoo between 1940 and 2025 was 20 December 1970, with 16.8 cm.
Are there tropical nights in Porvoo?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Porvoo.
What was the most extreme apparent temperature in Porvoo?
In Porvoo, between 1940 and 2025, the highest apparent temperature reached 33.8 °C on 29 July 1994, and the lowest was -43.2 °C on 10 January 1987.
Compare Porvoo with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Porvoo