Click on a day for an hourly weather forecast
The weather in Nagasaki in September is hot. The average temperatures are between 22°C and 27°C.
You can expect rain for roughly half of the month of September in Nagasaki. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Nagasaki in September 2025.
If you’re planning to visit Nagasaki in the near future, we highly recommend that you review the 14 day weather forecast for Nagasaki before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 10° / 5° | 8 | 19 | 4 | 84 mm | Awful | Nagasaki in January |
| February | 11° / 6° | 7 | 19 | 2 | 111 mm | Awful | Nagasaki in February |
| March | 14° / 9° | 7 | 23 | 0 | 121 mm | Ok | Nagasaki in March |
| April | 18° / 12° | 7 | 23 | 0 | 140 mm | Ok | Nagasaki in April |
| May | 22° / 16° | 7 | 24 | 0 | 145 mm | Ok | Nagasaki in May |
| June | 25° / 20° | 10 | 20 | 0 | 297 mm | Good | Nagasaki in June |
| July | 28° / 24° | 12 | 19 | 0 | 368 mm | Good | Nagasaki in July |
| August | 30° / 25° | 11 | 20 | 0 | 335 mm | Ok | Nagasaki in August |
| September | 27° / 22° | 8 | 22 | 0 | 198 mm | Good | Nagasaki in September |
| October | 23° / 17° | 4 | 27 | 0 | 104 mm | Perfect | Nagasaki in October |
| November | 17° / 13° | 5 | 25 | 0 | 126 mm | Good | Nagasaki in November |
| December | 12° / 7° | 7 | 22 | 2 | 109 mm | Awful | Nagasaki in December |