Suwa, Japan climate
Cfa Humid subtropical
Suwa has a strongly seasonal cool-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is August with an average daily high near 30°C, while the coldest is January averaging around −6°C at night. Precipitation totals about 1302 mm a year and is strongly seasonal — July alone averages 194 mm while December barely receives 42 mm.
☀️
Summers
Warm
Highs near 30°C in August.
❄️
Winters
Cold
Lows near −6°C in January.
🌧️
Rain
Wet
About 1302 mm of rain a year.
Wettest in July
⛅
Sky & trend
Often cloudy
Cloudy skies much of the year.
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresHours of sunshine per day
Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)Suwa climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 4 | 5 | 10 | 16 | 22 | 25 | 28 | 30 | 25 | 19 | 13 | 7 |
| Avg temp (°C) | −1 | 0 | 4 | 10 | 16 | 19 | 23 | 24 | 20 | 13 | 7 | 2 |
| Avg low (°C) | −6 | −5 | −1 | 4 | 10 | 15 | 20 | 20 | 16 | 9 | 3 | −2 |
| Precipitation (mm) | 43 | 51 | 89 | 93 | 112 | 155 | 194 | 141 | 177 | 137 | 69 | 42 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 4 | 5 | 10 | 16 | 22 | 25 |
| Avg temp (°C) | −1 | 0 | 4 | 10 | 16 | 19 |
| Avg low (°C) | −6 | −5 | −1 | 4 | 10 | 15 |
| Precipitation (mm) | 43 | 51 | 89 | 93 | 112 | 155 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 28 | 30 | 25 | 19 | 13 | 7 |
| Avg temp (°C) | 23 | 24 | 20 | 13 | 7 | 2 |
| Avg low (°C) | 20 | 20 | 16 | 9 | 3 | −2 |
| Precipitation (mm) | 194 | 141 | 177 | 137 | 69 | 42 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 63 | 64 | 65 | 65 | 69 | 81 | 79 | 70 | 75 | 70 | 62 | 61 |
| Relative humidity (%) | 88 | 85 | 80 | 76 | 75 | 80 | 83 | 82 | 84 | 85 | 85 | 86 |
| Wind speed (km/h) | 9.0 | 9.3 | 9.2 | 8.5 | 7.1 | 5.8 | 5.9 | 5.2 | 5.5 | 5.9 | 6.9 | 8.5 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 63 | 64 | 65 | 65 | 69 | 81 |
| Relative humidity (%) | 88 | 85 | 80 | 76 | 75 | 80 |
| Wind speed (km/h) | 9.0 | 9.3 | 9.2 | 8.5 | 7.1 | 5.8 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 79 | 70 | 75 | 70 | 62 | 61 |
| Relative humidity (%) | 83 | 82 | 84 | 85 | 85 | 86 |
| Wind speed (km/h) | 5.9 | 5.2 | 5.5 | 5.9 | 6.9 | 8.5 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from the Japan Meteorological Agency, measured at Suwa, inside the city.
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.