Climate averages 1991–2020
Nagano 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 Nagano: daytime highs average 28.1°C and nights cool to about 19.9°C. By daytime temperature it is the warmest month of the year.
Expect about 169 mm of rain on roughly 20 days, which makes August a wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 34 min on an average August day.
The nearest other city in this atlas is Ueda (29 km away). In August its highs average 28.7°C, 0.6°C warmer than Nagano, with 134 mm of rain.
Among the 303 cities listed in Japan, Nagano ranks joint 242nd 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; Nagano is 1.1°C cooler than that mean.
From August to September, average highs fall by 4.2°C to 23.9°C, and monthly rainfall rises from 169 mm to 182 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
Nagano climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.1°C-4.7°C | -4.7°C | 148 | 22.8 | 10.010 h |
| February | 3.2°C-4.4°C | -4.4°C | 121 | 19.1 | 10.811 h |
| March | 7.1°C-1.5°C | -1.5°C | 138 | 18.6 | 11.912 h |
| April | 13.9°C3.2°C | 3.2°C | 115 | 14.6 | 13.113 h |
| May | 20.6°C9.7°C | 9.7°C | 133 | 14.7 | 14.114 h |
| June | 23.7°C14.7°C | 14.7°C | 178 | 18.1 | 14.615 h |
| July | 26.9°C19.0°C | 19.0°C | 243 | 21.7 | 14.414 h |
| August, selected | 28.1°C19.9°C | 19.9°C | 169 | 19.5 | 13.614 h |
| September | 23.9°C15.9°C | 15.9°C | 182 | 17.0 | 12.412 h |
| October | 18.0°C9.5°C | 9.5°C | 161 | 15.6 | 11.311 h |
| November | 12.0°C3.2°C | 3.2°C | 116 | 16.4 | 10.310 h |
| December | 5.3°C-2.3°C | -2.3°C | 138 | 20.4 | 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
- Ueda in AugustJapan · 29 kmHigh 28.7°C · Low 20.2°C · 134 mm rain
- Azumino in AugustJapan · 48 kmHigh 28.3°C · Low 20.3°C · 155 mm rain
- Matsumoto in AugustJapan · 50 kmHigh 28.3°C · Low 20.0°C · 155 mm rain
- Saku in AugustJapan · 55 kmHigh 27.8°C · Low 20.2°C · 174 mm rain
- Jōetsu in AugustJapan · 56 kmHigh 29.3°C · Low 22.2°C · 122 mm rain
- Shibukawa in AugustJapan · 75 kmHigh 28.2°C · Low 21.4°C · 157 mm rain
- Takasaki in AugustJapan · 82 kmHigh 27.8°C · Low 20.9°C · 225 mm rain
- Maebashi in AugustJapan · 85 kmHigh 28.3°C · Low 21.3°C · 157 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 Nagano) is explained once on the Nagano year overview and on the Sources, method and limits page.