Koshu Weather in September

September in Koshu brings high temperatures, with daytime highs of 23°C (73°F) and nights around 15°C (59°F). It's also the wettest month of the year, so an umbrella is a must.

Rainfall in Koshu in September

Koshu is in the rainy season in September, with rain on around 19 days and an average of 240 mm (9.4 in). Rain during the rainy season is significant rather than just light drizzle. Expect proper showers on most rainy days.

Temperature in Koshu in September

Expect highs of 23°C (73°F) in Koshu in September, with nights dropping to around 15°C (59°F). This month falls in the summer season. Conditions stay fairly consistent through the month, making it easier to plan what to wear. With lows of 15°C (59°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest.

Sunshine in Koshu in September

The month brings about 152 hours of sunlight, offering a comfortable mix of sun and rainy moments.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. May typically offers the best weather for Koshu.

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Japan, check out our Koshu's climate page.

Koshu Temperature in September

Min Temperature 15°C (59°F)  

Max Temperature 23°C (73°F)  

Chance of Rain 64%  

Precipitation 240 mm (9.4 in)  

Rainy days 19 days  

Humidity 71% *  

Sunshine 152 hours *  

Percentage Sunshine *  

* Data from: Yamanashi, Japan (4 KM, 2 Miles).

What to Wear in Koshu in September

Comfortable temperatures call for an easy wardrobe in September. Pack summer basics like t-shirts and shorts, but include a light jacket for cooler moments. A pair of comfortable walking shoes is essential. It's going to pour! Pack a good poncho and prepare for very wet conditions. Sunglasses could come in handy during the sunnier parts of your trip.

What To Do in Koshu in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

7/10

Camping

6/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Japan, check out our Koshu's climate page.

More climate data for Koshu

Temperature Rainfall Sunshine Humidity

See the full Koshu climate overview or explore weather in Japan.