Click on a day for an hourly weather forecast
The temperatures in Yamanashi in September are comfortable with low of 15°C and and high up to 23°C.
You can expect rain for roughly half of the month of September in Yamanashi. 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 Yamanashi in September 2025.
If you’re planning to visit Yamanashi in the near future, we highly recommend that you review the 14 day weather forecast for Yamanashi before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 4° / -4° | 6 | 22 | 3 | 28 mm | Awful | Yamanashi in January |
| February | 5° / -3° | 7 | 17 | 3 | 47 mm | Awful | Yamanashi in February |
| March | 9° / 0° | 10 | 19 | 2 | 86 mm | Awful | Yamanashi in March |
| April | 14° / 4° | 9 | 21 | 1 | 87 mm | Ok | Yamanashi in April |
| May | 19° / 10° | 9 | 22 | 0 | 75 mm | Ok | Yamanashi in May |
| June | 22° / 14° | 12 | 18 | 0 | 94 mm | Ok | Yamanashi in June |
| July | 26° / 18° | 16 | 16 | 0 | 115 mm | Good | Yamanashi in July |
| August | 27° / 19° | 13 | 18 | 0 | 75 mm | Good | Yamanashi in August |
| September | 23° / 15° | 11 | 19 | 0 | 109 mm | Good | Yamanashi in September |
| October | 17° / 10° | 9 | 22 | 0 | 117 mm | Ok | Yamanashi in October |
| November | 13° / 4° | 6 | 24 | 0 | 50 mm | Ok | Yamanashi in November |
| December | 7° / -1° | 5 | 25 | 1 | 37 mm | Ok | Yamanashi in December |