Climate averages 1991–2020
Iwamizawa weather
in August.
A warm, wet month: the warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a warm month in Iwamizawa: daytime highs average 24.4°C and nights cool to about 17.5°C. By daytime temperature it is the warmest month of the year.
Expect about 161 mm of rain on roughly 13 days, which makes August a wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 13 h 57 min on an average August day.
The nearest other city in this atlas is Ebetsu (20 km away). In August its highs average 24.1°C, about as warm as Iwamizawa, with 171 mm of rain.
Among the 303 cities listed in Japan, Iwamizawa ranks joint 292nd of 303 for the warmest August highs and joint 191st of 303 for the driest August (rainfall, lowest first). The mean August high of those 303 cities is 29.2°C; Iwamizawa is 4.8°C cooler than that mean.
From August to September, average highs fall by 3.6°C to 20.8°C, and monthly rainfall falls from 161 mm to 126 mm.
The annual picture
August in context
Monthly precipitation
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
Iwamizawa climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -3.5°C-10.8°C | -10.8°C | 49 | 12.9 | 9.49 h |
| February | -2.5°C-10.0°C | -10.0°C | 43 | 10.8 | 10.510 h |
| March | 1.9°C-5.9°C | -5.9°C | 57 | 11.6 | 11.912 h |
| April | 9.5°C0.1°C | 0.1°C | 67 | 11.8 | 13.413 h |
| May | 16.2°C6.8°C | 6.8°C | 83 | 11.4 | 14.615 h |
| June | 20.1°C11.8°C | 11.8°C | 64 | 9.6 | 15.315 h |
| July | 23.7°C16.3°C | 16.3°C | 113 | 11.5 | 15.015 h |
| August, selected | 24.4°C17.5°C | 17.5°C | 161 | 12.5 | 14.014 h |
| September | 20.8°C13.1°C | 13.1°C | 126 | 13.2 | 12.513 h |
| October | 14.4°C6.3°C | 6.3°C | 92 | 13.6 | 11.111 h |
| November | 6.7°C-0.5°C | -0.5°C | 87 | 16.1 | 9.810 h |
| December | -0.8°C-8.0°C | -8.0°C | 69 | 15.3 | 9.19 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet 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
- Ebetsu in AugustJapan · 20 kmHigh 24.1°C · Low 17.6°C · 171 mm rain
- Sapporo in AugustJapan · 36 kmHigh 24.6°C · Low 18.5°C · 191 mm rain
- Eniwa in AugustJapan · 37 kmHigh 23.6°C · Low 17.4°C · 171 mm rain
- Chitose in AugustJapan · 43 kmHigh 23.2°C · Low 17.8°C · 162 mm rain
- Otaru in AugustJapan · 61 kmHigh 24.4°C · Low 18.8°C · 163 mm rain
- Tomakomai in AugustJapan · 64 kmHigh 22.5°C · Low 18.2°C · 197 mm rain
- Asahikawa in AugustJapan · 80 kmHigh 24.1°C · Low 16.5°C · 171 mm rain
- Muroran in AugustJapan · 117 kmHigh 23.0°C · Low 18.7°C · 181 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 Iwamizawa) is explained once on the Iwamizawa year overview and on the Sources, method and limits page.