Hanko climate — normals and trends
Hanko (Finland) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 6.0 °C and it receives 660 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 August (16.6 °C on average) and the coldest is February (-3.2 °C). Rainfall peaks in August.
Hanko averages 95 frost days, 0 hot days (≥ 30 °C) and 131 rainy days per year.
Hanko has warmed by +2.1 °C between 1940 and 2025, or +0.25 °C per decade. This trend is statistically significant.
The number of frost days there went from about 113 to 77 per year over the period.
The hottest day of the period reached 24.6 °C (on 16 July 2021) and the coldest -28.2 °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
HankoUusimaa
- coords
- 59.83°, 22.95°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
6.0°C
Average daily high
7.2°C
Average daily low
5.0°C
Annual rainfall
660mm
Sunshine / day
7.9h
Mean relative humidity
83%
Average peak wind
33.1km/h
Seasonal range
19.8°C
Frost days (< 0 °C)
95 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
131 d/yr
Annual snowfall
97.6 cm
Average feels-like high
2.9 °C
Average feels-like low
-0.5 °C
Average peak gust
45.0 km/h
Tropical nights (≥ 20 °C)
1 d/yr
Solar radiation
10.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.1 °C
since 1940
+0.3 °C per decade · r² = 0.35 · 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
24.6 °C
16 July 2021
Coldest day
-28.2 °C
10 January 1987
Wettest day
55 mm
12 August 1972
Windiest day
81.1 km/h
6 August 1967
Strongest gust
122.8 km/h
23 January 1995
Hottest feels-like
27.8 °C
15 July 2021
Coldest feels-like
-37.5 °C
10 January 1987
Snowiest day
12.3 cm
22 December 2003
Sunniest day
17.5 h
23 June 2018
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 | 3.2 °C | +3.6 °C | 86 mm | +34 mm |
| Feb | 0.6 °C | +2.4 °C | 25 mm | -14 mm |
| Mar | 3.4 °C | +3.6 °C | 15 mm | -19 mm |
| Apr | 5.7 °C | +2.3 °C | 52 mm | +16 mm |
| May | 8.9 °C | +1.3 °C | 22 mm | -11 mm |
| Jun | 13.5 °C | +1.0 °C | 82 mm | +41 mm |
| Jul | 18.5 °C | +1.2 °C | 49 mm | -7 mm |
| Aug | 17.6 °C | +0.1 °C | 66 mm | -10 mm |
| Sep | 16.1 °C | +2.0 °C | 83 mm | +7 mm |
| Oct | 10.7 °C | +2.0 °C | 83 mm | +7 mm |
| Nov | 7.9 °C | +2.9 °C | 82 mm | +6 mm |
| Dec | 5.5 °C | +3.3 °C | 67 mm | -0 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 Hanko?
Hanko has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 6.0 °C and it receives 660 mm of precipitation per year.
What is the hottest day ever recorded in Hanko?
The hottest day measured in Hanko between 1940 and 2025 was 16 July 2021, reaching 24.6 °C.
What is the coldest day in Hanko?
The coldest day measured in Hanko between 1940 and 2025 was 10 January 1987, at -28.2 °C.
Does it snow in Hanko?
Yes. Hanko gets on average 97.6 cm of snow per year and has around 95 frost days.
Has the climate of Hanko warmed?
Yes: Hanko warmed by +2.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Hanko?
The wettest day measured in Hanko between 1940 and 2025 was 12 August 1972, with 55 mm of rain in 24 hours.
What was the windiest day in Hanko?
The windiest day measured in Hanko between 1940 and 2025 was 6 August 1967, with winds reaching 81.1 km/h.
What is the warmest month in Hanko?
The warmest month in Hanko is August (16.6 °C on average); the coldest is February (-3.2 °C).
How much does it rain in Hanko?
Hanko receives on average 660 mm of precipitation per year, spread over about 131 rainy days.
Is it sunny in Hanko?
Hanko gets on average 7.9 hours of sunshine per day, roughly 2,884 hours per year over 1940-2025.
What is the biggest single-day snowfall in Hanko?
The heaviest 24-hour snowfall measured in Hanko between 1940 and 2025 was 22 December 2003, with 12.3 cm.
Are there tropical nights in Hanko?
Yes: Hanko has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Hanko?
In Hanko, between 1940 and 2025, the highest apparent temperature reached 27.8 °C on 15 July 2021, and the lowest was -37.5 °C on 10 January 1987.
Compare Hanko with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Hanko