Home › Cities › Finland › Helsinki
Helsinki, Finland climate
Dfb Warm-summer humid continental
Helsinki has a seasonal cold-temperate climate (Warm-summer humid continental, Köppen Dfb). The hottest month is July with an average daily high near 23°C, while the coldest is February averaging around −8°C at night. Around 677 mm of precipitation falls each year, peaking in October (79 mm) and easing off in March (33 mm). At latitude 60°N, day length swings from 5.4 hours in midwinter to 18.6 hours at midsummer.
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsHelsinki climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | −2 | −2 | 2 | 9 | 16 | 20 | 23 | 21 | 16 | 9 | 3 | 0 |
| Avg temp (°C) | −4 | −5 | −1 | 5 | 11 | 15 | 18 | 17 | 12 | 6 | 1 | −2 |
| Avg low (°C) | −7 | −8 | −5 | 0 | 5 | 10 | 13 | 12 | 8 | 3 | −1 | −4 |
| Precipitation (mm) | 53 | 40 | 33 | 36 | 39 | 64 | 64 | 78 | 61 | 79 | 70 | 61 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | −2 | −2 | 2 | 9 | 16 | 20 |
| Avg temp (°C) | −4 | −5 | −1 | 5 | 11 | 15 |
| Avg low (°C) | −7 | −8 | −5 | 0 | 5 | 10 |
| Precipitation (mm) | 53 | 40 | 33 | 36 | 39 | 64 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 23 | 21 | 16 | 9 | 3 | 0 |
| Avg temp (°C) | 18 | 17 | 12 | 6 | 1 | −2 |
| Avg low (°C) | 13 | 12 | 8 | 3 | −1 | −4 |
| Precipitation (mm) | 64 | 78 | 61 | 79 | 70 | 61 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 18 | 14 | 12 | 11 | 10 | 13 | 11 | 14 | 13 | 16 | 16 | 19 |
| Days with high ≥ 32°C (days) | — | — | — | — | — | — | 0.2 | — | — | — | — | — |
| Days with low ≤ 0°C (days) | 28 | 26 | 27 | 15 | 3 | 0.0 | — | — | 2 | 9 | 17 | 24 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 18 | 14 | 12 | 11 | 10 | 13 |
| Days with high ≥ 32°C (days) | — | — | — | — | — | — |
| Days with low ≤ 0°C (days) | 28 | 26 | 27 | 15 | 3 | 0.0 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 11 | 14 | 13 | 16 | 16 | 19 |
| Days with high ≥ 32°C (days) | 0.2 | — | — | — | — | — |
| Days with low ≤ 0°C (days) | — | — | 2 | 9 | 17 | 24 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 75 | 70 | 65 | 66 | 62 | 65 | 63 | 63 | 67 | 75 | 77 | 77 |
| Clear days (≤ 30% cloud) | 2 | 3 | 4 | 4 | 5 | 3 | 4 | 5 | 3 | 2 | 2 | 2 |
| Partly cloudy days (30–70%) | 8 | 8 | 11 | 11 | 12 | 12 | 13 | 12 | 11 | 8 | 7 | 7 |
| Cloudy days (≥ 70%) | 21 | 17 | 15 | 15 | 14 | 14 | 14 | 14 | 15 | 21 | 21 | 22 |
| Relative humidity (%) | 98 | 98 | 93 | 83 | 77 | 78 | 80 | 82 | 86 | 92 | 96 | 97 |
| Wind speed (mph) | 1.8 | 1.8 | 1.7 | 1.4 | 1.1 | 1.0 | 1.1 | 1.2 | 1.4 | 1.5 | 1.6 | 1.8 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 75 | 70 | 65 | 66 | 62 | 65 |
| Clear days (≤ 30% cloud) | 2 | 3 | 4 | 4 | 5 | 3 |
| Partly cloudy days (30–70%) | 8 | 8 | 11 | 11 | 12 | 12 |
| Cloudy days (≥ 70%) | 21 | 17 | 15 | 15 | 14 | 14 |
| Relative humidity (%) | 98 | 98 | 93 | 83 | 77 | 78 |
| Wind speed (mph) | 1.8 | 1.8 | 1.7 | 1.4 | 1.1 | 1.0 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 63 | 63 | 67 | 75 | 77 | 77 |
| Clear days (≤ 30% cloud) | 4 | 5 | 3 | 2 | 2 | 2 |
| Partly cloudy days (30–70%) | 13 | 12 | 11 | 8 | 7 | 7 |
| Cloudy days (≥ 70%) | 14 | 14 | 15 | 21 | 21 | 22 |
| Relative humidity (%) | 80 | 82 | 86 | 92 | 96 | 97 |
| Wind speed (mph) | 1.1 | 1.2 | 1.4 | 1.5 | 1.6 | 1.8 |
Methodology & sources
Temperature & precipitation — 1991–2020 normals computed from 30 years of daily observations at Vantaa Helsinki-vantaan Lentoa, a weather station, about 18 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.