Our trip to Mount Koya coincided with snowfall (the wind and snow intensified around noon), but we were still able to visit Danjo Garan, Kongobuji Temple, Okunoin, and other places. I am especially grateful to our guide and driver for making the right assessment of the entire trip, which allowed everyone to descend the mountain safely and warmly. Although it was a bit of a pity that the trip ended early due to the snow, they were very honest and proactively refunded part of the tour fee (on the other hand, leaving some regrets in the itinerary gives us a reason to start the next trip).
The atmosphere, amenities, hospitalities....everything well exceeds my expectation.
Anonymous User
Solo traveler
Koyasan Weather, Climate and Best Time to Visit
Data source:Meteostat Update date:2025-09
Koyasan year round climate
Spring (March–May): Average 10.6–18.6°C, mild and comfortable climate, but with relatively high rainfall, especially in May. Common activities: Visiting Koyasan temples, hiking (be aware of changing weather conditions). Recommended clothing: Light jacket, long-sleeved shirt, rain gear.
Summer (June–August): Average 22.6–28.7°C, hot and humid, with occasional showers. Common activities: Visiting temples, experiencing local culture, escaping the heat in the mountains. Recommended clothing: Breathable and sweat-wicking clothing, sun hat, rain gear.
Autumn (September–November): Average 15.7–27.0°C, comfortable and pleasant climate, with reduced rainfall. Common activities: Autumn leaves viewing (in some areas), visiting temples, hiking. Recommended clothing: Light jacket, long-sleeved shirt.
Winter (December–February): Average 7.2–9.8°C, cold and dry, with little rain. Common activities: Visiting temples, experiencing onsen (in nearby areas). Recommended clothing: Warm jacket, sweater, scarf, gloves.
Koyasan climatological average
Annual average temperature: approx. 17.6°C / Annual rainfall: approx. 1794 mm / Summer humidity: 70%–80% / Rainiest month: May
Koyasan monthly average temperature and precipitation
Month
Air temperature (°C)
Precipitation (mm)
January
7.2°C
63.9
February
7.2°C
59.2
March
10.6°C
113.6
April
15.4°C
163.5
May
18.6°C
313.2
June
22.6°C
285.1
July
27.4°C
200.3
August
28.7°C
130.6
September
27°C
161.5
October
20.5°C
141
November
15.7°C
101.2
December
9.8°C
61.5
Koyasan weather for the next seven days
2/15
Sunday
Partly Cloudy
16.2°C/4.9°C
2/16
Monday
Patchy rain nearby
8.2°C/-0.1°C
2/17
Tuesday
Sunny
10.4°C/-1.4°C
2/18
Wednesday
Partly Cloudy
9.6°C/-0.4°C
2/19
Thursday
Sunny
10.3°C/-0.7°C
2/20
Friday
Partly Cloudy
13.2°C/1.3°C
2/21
Saturday
Patchy rain nearby
14.3°C/4.4°C
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