Home › Cities › Japan › Iwamizawa
Iwamizawa, Japan climate
Dfb Warm-summer humid continental
Iwamizawa has a strongly seasonal cool-temperate climate (Warm-summer humid continental, Köppen Dfb). The hottest month is August with an average daily high near 26°C, while the coldest is January averaging around −9°C at night. Around 1259 mm of precipitation falls each year, peaking in August (161 mm) and easing off in April (53 mm).
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)Iwamizawa climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | −2 | −1 | 4 | 11 | 18 | 22 | 25 | 26 | 22 | 16 | 8 | 1 |
| Avg temp (°C) | −5 | −5 | 0 | 6 | 12 | 16 | 20 | 21 | 17 | 11 | 4 | −3 |
| Avg low (°C) | −9 | −9 | −5 | 1 | 7 | 12 | 17 | 18 | 13 | 6 | 0 | −6 |
| Precipitation (mm) | 119 | 85 | 59 | 53 | 84 | 69 | 112 | 161 | 142 | 110 | 119 | 145 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | −2 | −1 | 4 | 11 | 18 | 22 |
| Avg temp (°C) | −5 | −5 | 0 | 6 | 12 | 16 |
| Avg low (°C) | −9 | −9 | −5 | 1 | 7 | 12 |
| Precipitation (mm) | 119 | 85 | 59 | 53 | 84 | 69 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 25 | 26 | 22 | 16 | 8 | 1 |
| Avg temp (°C) | 20 | 21 | 17 | 11 | 4 | −3 |
| Avg low (°C) | 17 | 18 | 13 | 6 | 0 | −6 |
| Precipitation (mm) | 112 | 161 | 142 | 110 | 119 | 145 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 91 | 86 | 79 | 72 | 71 | 73 | 76 | 73 | 72 | 75 | 86 | 91 |
| Relative humidity (%) | 92 | 90 | 87 | 82 | 82 | 84 | 86 | 86 | 85 | 84 | 87 | 91 |
| Wind speed (m/s) | 3.0 | 3.2 | 3.2 | 3.2 | 2.9 | 2.3 | 2.2 | 2.1 | 2.3 | 2.6 | 2.8 | 2.9 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 91 | 86 | 79 | 72 | 71 | 73 |
| Relative humidity (%) | 92 | 90 | 87 | 82 | 82 | 84 |
| Wind speed (m/s) | 3.0 | 3.2 | 3.2 | 3.2 | 2.9 | 2.3 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 76 | 73 | 72 | 75 | 86 | 91 |
| Relative humidity (%) | 86 | 86 | 85 | 84 | 87 | 91 |
| Wind speed (m/s) | 2.2 | 2.1 | 2.3 | 2.6 | 2.8 | 2.9 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from the Japan Meteorological Agency, measured at Iwamizawa, about 2 km from the city centre.
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.