Koyasan Weather in September

September in Koyasan brings high temperatures around 28°C (82°F) during the day, dropping to 19°C (66°F) at night, with quite a bit of rainfall expected, averaging around 214 mm (8.4 in) for the month.

Rainfall in Koyasan in September

Based on our climate data of the past 30 years, about 18 days of rain are anticipated, with 214 mm (8.4 in) on average. Expect frequent rainfall this month, and not just light drizzle. When it rains, it tends to come down hard.

Temperature in Koyasan in September

Temperatures in Koyasan in September top out at 28°C (82°F) and drop to 19°C (66°F) overnight. This gives the month a fairly typical daily rhythm, with warmer afternoons and more comfortable nights. With overnight lows of 19°C (66°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep.

Sunshine in Koyasan in September

With about 162 hours of sunshine, the area enjoys a nice balance of sun and overcast, creating a pleasant environment.

For Koyasan itself, May generally stands out with the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

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 Koyasan's climate page.

Koyasan Temperature in September

Min Temperature 19°C (66°F)  

Max Temperature 28°C (82°F)  

Chance of Rain 61%  

Precipitation 214 mm (8.4 in)  

Rainy days 18 days  

Humidity 73% *  

Sunshine 162 hours *  

Percentage Sunshine *  

* Data from: Wakayama, Japan (37 KM, 23 Miles).

What to Wear in Koyasan in September

Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Also bring a poncho, it will rain a lot! Waterproof everything you can. It won't hurt to bring your sunglasses along, as you'll see some sunny periods.

What To Do in Koyasan in September

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

Swimming

7/10

Cycling

7/10

Walking

7/10

Camping

6/10

Outdoor sports

7/10

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 Koyasan's climate page.

More climate data for Koyasan

Temperature Rainfall Sunshine Humidity

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