Climate averages 1991–2020
Iwakuni weather
in August.
A hot, wet month: the warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Iwakuni: daytime highs average 29.8°C and nights cool to about 24.4°C. By daytime temperature it is the warmest month of the year.
Expect about 169 mm of rain on roughly 14 days, which makes August a wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 26 min on an average August day.
The nearest other city in this atlas is Hatsukaichi (23 km away). In August its highs average 30.9°C, 1.0°C warmer than Iwakuni, with 169 mm of rain.
Among the 303 cities listed in Japan, Iwakuni ranks joint 125th of 303 for the warmest August highs and joint 214th of 303 for the driest August (rainfall, lowest first). The mean August high of those 303 cities is 29.2°C; Iwakuni is 0.7°C warmer than that mean.
From August to September, average highs fall by 3.3°C to 26.5°C, and monthly rainfall rises from 169 mm to 185 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Iwakuni climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 8.5°C2.8°C | 2.8°C | 50 | 6.2 | 10.210 h |
| February | 9.6°C2.8°C | 2.8°C | 69 | 8.0 | 10.911 h |
| March | 13.0°C5.3°C | 5.3°C | 116 | 10.1 | 11.912 h |
| April | 17.8°C9.9°C | 9.9°C | 138 | 9.7 | 13.013 h |
| May | 22.2°C14.8°C | 14.8°C | 158 | 10.3 | 13.914 h |
| June | 25.1°C19.1°C | 19.1°C | 234 | 13.9 | 14.414 h |
| July | 28.7°C23.4°C | 23.4°C | 255 | 15.2 | 14.214 h |
| August, selected | 29.8°C24.4°C | 24.4°C | 169 | 14.4 | 13.413 h |
| September | 26.5°C20.9°C | 20.9°C | 185 | 11.7 | 12.412 h |
| October | 21.5°C15.5°C | 15.5°C | 116 | 8.0 | 11.411 h |
| November | 16.1°C10.1°C | 10.1°C | 72 | 7.1 | 10.410 h |
| December | 10.8°C5.1°C | 5.1°C | 60 | 6.7 | 9.910 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Hatsukaichi in AugustJapan · 23 kmHigh 30.9°C · Low 24.3°C · 169 mm rain
- Kure in AugustJapan · 33 kmHigh 28.4°C · Low 24.2°C · 120 mm rain
- Hiroshima in AugustJapan · 34 kmHigh 30.4°C · Low 23.8°C · 157 mm rain
- Shūnan in AugustJapan · 37 kmHigh 28.3°C · Low 22.6°C · 147 mm rain
- Higashihiroshima in AugustJapan · 55 kmHigh 29.6°C · Low 23.1°C · 132 mm rain
- Hōfu in AugustJapan · 61 kmHigh 30.3°C · Low 24.3°C · 135 mm rain
- Matsuyama in AugustJapan · 62 kmHigh 30.7°C · Low 24.9°C · 156 mm rain
- Yamaguchi in AugustJapan · 69 kmHigh 30.2°C · Low 23.4°C · 167 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Iwakuni) is explained once on the Iwakuni year overview and on the Sources, method and limits page.
Hatsukaichi lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.