Climate averages 1991–2020
Saku weather
in September.
A warm, very wet month: the 3rd warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Saku: daytime highs average 23.7°C and nights cool to about 16.4°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 187 mm of rain on roughly 18 days, which makes September a very wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 27 min on an average September day.
The nearest other city in this atlas is Ueda (27 km away). In September its highs average 24.4°C, 0.6°C warmer than Saku, with 161 mm of rain.
Among the 303 cities listed in Japan, Saku ranks joint 266th of 303 for the warmest September highs and joint 152nd of 303 for the driest September (rainfall, lowest first). The mean September high of those 303 cities is 25.7°C; Saku is 1.9°C cooler than that mean.
From September to October, average highs fall by 5.7°C to 18.1°C, and monthly rainfall falls from 187 mm to 161 mm.
The annual picture
September 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
Saku climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 3.9°C-4.4°C | -4.4°C | 55 | 7.6 | 10.010 h |
| February | 4.8°C-4.4°C | -4.4°C | 58 | 8.1 | 10.811 h |
| March | 9.0°C-0.9°C | -0.9°C | 99 | 11.7 | 11.912 h |
| April | 15.6°C4.8°C | 4.8°C | 102 | 12.3 | 13.113 h |
| May | 20.6°C10.6°C | 10.6°C | 131 | 14.9 | 14.114 h |
| June | 23.4°C15.3°C | 15.3°C | 197 | 19.8 | 14.615 h |
| July | 27.0°C19.3°C | 19.3°C | 220 | 21.6 | 14.414 h |
| August | 27.8°C20.2°C | 20.2°C | 174 | 21.5 | 13.514 h |
| September, selected | 23.7°C16.4°C | 16.4°C | 187 | 17.6 | 12.412 h |
| October | 18.1°C10.1°C | 10.1°C | 161 | 12.9 | 11.311 h |
| November | 12.7°C3.9°C | 3.9°C | 64 | 7.8 | 10.310 h |
| December | 6.9°C-1.1°C | -1.1°C | 48 | 7.9 | 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
September in nearby cities
- Ueda in SeptemberJapan · 27 kmHigh 24.4°C · Low 16.2°C · 161 mm rain
- Matsumoto in SeptemberJapan · 46 kmHigh 24.3°C · Low 16.2°C · 199 mm rain
- Takasaki in SeptemberJapan · 50 kmHigh 24.1°C · Low 17.5°C · 257 mm rain
- Azumino in SeptemberJapan · 54 kmHigh 24.2°C · Low 16.3°C · 199 mm rain
- Shibukawa in SeptemberJapan · 55 kmHigh 24.4°C · Low 18.0°C · 201 mm rain
- Nagano in SeptemberJapan · 55 kmHigh 23.9°C · Low 15.9°C · 182 mm rain
- Maebashi in SeptemberJapan · 57 kmHigh 24.5°C · Low 17.9°C · 201 mm rain
- Kai in SeptemberJapan · 59 kmHigh 25.3°C · Low 17.8°C · 185 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 Saku) is explained once on the Saku year overview and on the Sources, method and limits page.