Climate averages 1991–2020
Tomakomai weather
in August.
A warm, very 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 Tomakomai: daytime highs average 22.5°C and nights cool to about 18.2°C. By daytime temperature it is the warmest month of the year.
Expect about 197 mm of rain on roughly 15 days, which makes August a very wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 13 h 55 min on an average August day.
The nearest other city in this atlas is Chitose (21 km away). In August its highs average 23.2°C, 0.7°C warmer than Tomakomai, with 162 mm of rain.
Among the 303 cities listed in Japan, Tomakomai ranks 302nd of 303 for the warmest August highs and 281st of 303 for the driest August (rainfall, lowest first). The mean August high of those 303 cities is 29.2°C; Tomakomai is 6.7°C cooler than that mean.
From August to September, average highs fall by 2.4°C to 20.1°C, and monthly rainfall falls from 197 mm to 177 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
Tomakomai climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -2.0°C-7.5°C | -7.5°C | 44 | 7.1 | 9.49 h |
| February | -1.3°C-7.4°C | -7.4°C | 44 | 7.4 | 10.511 h |
| March | 2.2°C-4.0°C | -4.0°C | 63 | 10.3 | 11.912 h |
| April | 7.5°C1.0°C | 1.0°C | 78 | 11.5 | 13.413 h |
| May | 12.7°C6.7°C | 6.7°C | 109 | 11.8 | 14.615 h |
| June | 16.7°C11.6°C | 11.6°C | 100 | 11.3 | 15.315 h |
| July | 20.6°C16.1°C | 16.1°C | 138 | 13.7 | 15.015 h |
| August, selected | 22.5°C18.2°C | 18.2°C | 197 | 14.5 | 13.914 h |
| September | 20.1°C15.1°C | 15.1°C | 177 | 15.0 | 12.513 h |
| October | 14.3°C8.8°C | 8.8°C | 110 | 11.8 | 11.111 h |
| November | 7.3°C2.0°C | 2.0°C | 78 | 10.8 | 9.810 h |
| December | 0.7°C-4.2°C | -4.2°C | 63 | 8.7 | 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
- Chitose in AugustJapan · 21 kmHigh 23.2°C · Low 17.8°C · 162 mm rain
- Eniwa in AugustJapan · 29 kmHigh 23.6°C · Low 17.4°C · 171 mm rain
- Sapporo in AugustJapan · 52 kmHigh 24.6°C · Low 18.5°C · 191 mm rain
- Ebetsu in AugustJapan · 53 kmHigh 24.1°C · Low 17.6°C · 171 mm rain
- Muroran in AugustJapan · 62 kmHigh 23.0°C · Low 18.7°C · 181 mm rain
- Iwamizawa in AugustJapan · 64 kmHigh 24.4°C · Low 17.5°C · 161 mm rain
- Otaru in AugustJapan · 79 kmHigh 24.4°C · Low 18.8°C · 163 mm rain
- Hakodate in AugustJapan · 119 kmHigh 23.7°C · Low 19.7°C · 206 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 Tomakomai) is explained once on the Tomakomai year overview and on the Sources, method and limits page.