Climate averages 1991–2020
Koga weather
in August.
A hot, wet month: the warmest and the 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Koga: daytime highs average 29.8°C and nights cool to about 22.6°C. By daytime temperature it is the warmest month of the year.
Expect about 161 mm of rain on roughly 16 days, which makes August a wet month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 32 min on an average August day.
The nearest other city in this atlas is Kazo (13 km away). In August its highs average 30.0°C, about as warm as Koga, with 128 mm of rain.
Among the 303 cities listed in Japan, Koga ranks joint 125th 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; Koga is 0.6°C warmer than that mean.
From August to September, average highs fall by 3.8°C to 26.0°C, and monthly rainfall rises from 161 mm to 206 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
Koga climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 7.6°C-2.1°C | -2.1°C | 55 | 6.0 | 10.010 h |
| February | 8.8°C-1.3°C | -1.3°C | 55 | 6.9 | 10.811 h |
| March | 12.5°C1.9°C | 1.9°C | 106 | 11.6 | 11.912 h |
| April | 17.7°C7.1°C | 7.1°C | 120 | 12.6 | 13.113 h |
| May | 22.3°C12.6°C | 12.6°C | 153 | 13.7 | 14.114 h |
| June | 25.0°C17.2°C | 17.2°C | 177 | 16.5 | 14.615 h |
| July | 28.4°C21.3°C | 21.3°C | 209 | 18.7 | 14.414 h |
| August, selected | 29.8°C22.6°C | 22.6°C | 161 | 16.3 | 13.514 h |
| September | 26.0°C19.2°C | 19.2°C | 206 | 16.2 | 12.412 h |
| October | 20.5°C13.0°C | 13.0°C | 200 | 13.9 | 11.311 h |
| November | 15.2°C6.3°C | 6.3°C | 88 | 9.4 | 10.310 h |
| December | 10.0°C0.7°C | 0.7°C | 54 | 6.8 | 9.710 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
- Kazo in AugustJapan · 13 kmHigh 30.0°C · Low 22.9°C · 128 mm rain
- Kukichūō in AugustJapan · 13 kmHigh 30.1°C · Low 22.9°C · 118 mm rain
- Oyama in AugustJapan · 15 kmHigh 29.5°C · Low 22.3°C · 161 mm rain
- Tatebayashi in AugustJapan · 18 kmHigh 29.5°C · Low 22.4°C · 171 mm rain
- Sano in AugustJapan · 19 kmHigh 29.5°C · Low 22.4°C · 171 mm rain
- Kōnosu in AugustJapan · 22 kmHigh 29.8°C · Low 22.8°C · 128 mm rain
- Tochigi in AugustJapan · 22 kmHigh 29.3°C · Low 22.2°C · 207 mm rain
- Kasukabe in AugustJapan · 22 kmHigh 30.1°C · Low 23.1°C · 118 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 Koga) is explained once on the Koga year overview and on the Sources, method and limits page.
Oyama lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.