Climate averages 1991–2020
Kumamoto weather
in September.
A warm, wet month: the 3rd warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Kumamoto: daytime highs average 27.5°C and nights cool to about 20.8°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 156 mm of rain on roughly 12 days, which makes September a wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 24 min on an average September day.
The nearest other city in this atlas is Ōmuta (34 km away). In September its highs average 27.3°C, about as warm as Kumamoto, with 165 mm of rain.
Among the 303 cities listed in Japan, Kumamoto ranks joint 16th of 303 for the warmest September highs and joint 37th of 303 for the driest September (rainfall, lowest first). The mean September high of those 303 cities is 25.7°C; Kumamoto is 1.8°C warmer than that mean.
From September to October, average highs fall by 5.0°C to 22.5°C, and monthly rainfall falls from 156 mm to 98 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
Kumamoto climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 9.0°C3.0°C | 3.0°C | 78 | 10.6 | 10.310 h |
| February | 10.5°C3.4°C | 3.4°C | 99 | 10.4 | 11.011 h |
| March | 14.0°C6.1°C | 6.1°C | 142 | 13.0 | 12.012 h |
| April | 18.8°C10.5°C | 10.5°C | 154 | 12.1 | 13.013 h |
| May | 23.2°C15.2°C | 15.2°C | 178 | 11.9 | 13.814 h |
| June | 25.7°C19.4°C | 19.4°C | 403 | 17.0 | 14.314 h |
| July | 29.0°C23.2°C | 23.2°C | 301 | 16.2 | 14.114 h |
| August | 30.4°C24.0°C | 24.0°C | 135 | 13.0 | 13.413 h |
| September, selected | 27.5°C20.8°C | 20.8°C | 156 | 11.7 | 12.412 h |
| October | 22.5°C15.1°C | 15.1°C | 98 | 8.3 | 11.411 h |
| November | 16.9°C9.7°C | 9.7°C | 92 | 8.8 | 10.511 h |
| December | 11.2°C4.9°C | 4.9°C | 84 | 10.0 | 10.010 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
- Ōmuta in SeptemberJapan · 34 kmHigh 27.3°C · Low 21.0°C · 165 mm rain
- Honmachi in SeptemberJapan · 35 kmHigh 27.9°C · Low 21.5°C · 174 mm rain
- Kurume in SeptemberJapan · 59 kmHigh 27.5°C · Low 19.6°C · 180 mm rain
- Saga in SeptemberJapan · 60 kmHigh 27.1°C · Low 20.2°C · 189 mm rain
- Amakusa in SeptemberJapan · 61 kmHigh 28.1°C · Low 22.1°C · 197 mm rain
- Isahaya in SeptemberJapan · 61 kmHigh 26.5°C · Low 21.9°C · 202 mm rain
- Tosu in SeptemberJapan · 64 kmHigh 27.4°C · Low 19.8°C · 180 mm rain
- Ōmura in SeptemberJapan · 70 kmHigh 27.2°C · Low 22.5°C · 188 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 Kumamoto) is explained once on the Kumamoto year overview and on the Sources, method and limits page.