Climate averages 1991–2020
Nagasaki 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 Nagasaki: daytime highs average 26.7°C and nights cool to about 22.8°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 202 mm of rain on roughly 12 days, which makes September a very wet month (the 10th 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 Isahaya (18 km away). In September its highs average 26.5°C, about as warm as Nagasaki, with 202 mm of rain.
Among the 303 cities listed in Japan, Nagasaki ranks joint 83rd of 303 for the warmest September highs and joint 201st of 303 for the driest September (rainfall, lowest first). The mean September high of those 303 cities is 25.7°C; Nagasaki is 1.0°C warmer than that mean.
From September to October, average highs fall by 4.4°C to 22.3°C, and monthly rainfall falls from 202 mm to 112 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
Nagasaki climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 9.8°C6.3°C | 6.3°C | 79 | 10.9 | 10.310 h |
| February | 10.7°C6.5°C | 6.5°C | 100 | 10.2 | 11.011 h |
| March | 13.5°C8.9°C | 8.9°C | 149 | 12.0 | 12.012 h |
| April | 17.4°C12.6°C | 12.6°C | 167 | 11.4 | 13.013 h |
| May | 21.2°C16.7°C | 16.7°C | 197 | 10.8 | 13.814 h |
| June | 24.1°C20.4°C | 20.4°C | 444 | 16.5 | 14.314 h |
| July | 27.4°C24.3°C | 24.3°C | 346 | 16.6 | 14.114 h |
| August | 29.1°C25.6°C | 25.6°C | 185 | 13.7 | 13.413 h |
| September, selected | 26.7°C22.8°C | 22.8°C | 202 | 11.9 | 12.412 h |
| October | 22.3°C18.3°C | 18.3°C | 112 | 7.5 | 11.411 h |
| November | 17.2°C13.4°C | 13.4°C | 106 | 9.1 | 10.511 h |
| December | 12.2°C8.6°C | 8.6°C | 92 | 10.3 | 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
- Isahaya in SeptemberJapan · 18 kmHigh 26.5°C · Low 21.9°C · 202 mm rain
- Ōmura in SeptemberJapan · 20 kmHigh 27.2°C · Low 22.5°C · 188 mm rain
- Amakusa in SeptemberJapan · 43 kmHigh 28.1°C · Low 22.1°C · 197 mm rain
- Sasebo in SeptemberJapan · 49 kmHigh 27.0°C · Low 22.0°C · 186 mm rain
- Ōmuta in SeptemberJapan · 62 kmHigh 27.3°C · Low 21.0°C · 165 mm rain
- Saga in SeptemberJapan · 66 kmHigh 27.1°C · Low 20.2°C · 189 mm rain
- Honmachi in SeptemberJapan · 72 kmHigh 27.9°C · Low 21.5°C · 174 mm rain
- Kumamoto in SeptemberJapan · 76 kmHigh 27.5°C · Low 20.8°C · 156 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 Nagasaki) is explained once on the Nagasaki year overview and on the Sources, method and limits page.
Isahaya lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.