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Iwakuni, Japan climate
Cfa Humid subtropical
Iwakuni has a seasonal mild-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is August with an average daily high near 33°C, while the coldest is January averaging around 2°C at night. Precipitation totals about 1695 mm a year and is strongly seasonal — July alone averages 288 mm while January barely receives 51 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)Iwakuni climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 10 | 11 | 14 | 20 | 24 | 27 | 31 | 33 | 29 | 24 | 18 | 12 |
| Avg temp (°C) | 5 | 6 | 9 | 14 | 19 | 23 | 27 | 28 | 24 | 19 | 13 | 8 |
| Avg low (°C) | 2 | 2 | 5 | 10 | 15 | 19 | 24 | 25 | 21 | 14 | 9 | 4 |
| Precipitation (mm) | 51 | 73 | 131 | 157 | 181 | 258 | 288 | 148 | 169 | 109 | 72 | 58 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 10 | 11 | 14 | 20 | 24 | 27 |
| Avg temp (°C) | 5 | 6 | 9 | 14 | 19 | 23 |
| Avg low (°C) | 2 | 2 | 5 | 10 | 15 | 19 |
| Precipitation (mm) | 51 | 73 | 131 | 157 | 181 | 258 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 31 | 33 | 29 | 24 | 18 | 12 |
| Avg temp (°C) | 27 | 28 | 24 | 19 | 13 | 8 |
| Avg low (°C) | 24 | 25 | 21 | 14 | 9 | 4 |
| Precipitation (mm) | 288 | 148 | 169 | 109 | 72 | 58 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 81 | 79 | 73 | 68 | 68 | 79 | 75 | 67 | 72 | 68 | 72 | 78 |
| Relative humidity (%) | 76 | 74 | 74 | 76 | 78 | 83 | 85 | 82 | 80 | 76 | 75 | 76 |
| Wind speed (mph) | 7.2 | 7.1 | 6.8 | 5.6 | 4.5 | 3.9 | 4.0 | 4.3 | 5.5 | 6.5 | 6.4 | 6.9 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 81 | 79 | 73 | 68 | 68 | 79 |
| Relative humidity (%) | 76 | 74 | 74 | 76 | 78 | 83 |
| Wind speed (mph) | 7.2 | 7.1 | 6.8 | 5.6 | 4.5 | 3.9 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 75 | 67 | 72 | 68 | 72 | 78 |
| Relative humidity (%) | 85 | 82 | 80 | 76 | 75 | 76 |
| Wind speed (mph) | 4.0 | 4.3 | 5.5 | 6.5 | 6.4 | 6.9 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from the Japan Meteorological Agency, measured at Otake, about 7 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.