Our tour guide, Yan Lei, provided a thorough explanation. The scenery was exceptionally beautiful. I recommend eating a hearty lunch, as you'll likely be quite hungry after visiting Okunoin.
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 51–65°F, 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 72–83°F, 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 60–80°F, 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 44–49°F, 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. 63.7°F / Annual rainfall: approx. 1794 mm / Summer humidity: 70%–80% / Rainiest month: May
Koyasan monthly average temperature and precipitation
Month
Air temperature (°F)
Precipitation (mm)
January
45°F
63.9
February
45°F
59.2
March
51.1°F
113.6
April
59.7°F
163.5
May
65.5°F
313.2
June
72.7°F
285.1
July
81.3°F
200.3
August
83.7°F
130.6
September
80.6°F
161.5
October
68.9°F
141
November
60.3°F
101.2
December
49.6°F
61.5
Koyasan weather for the next seven days
4/1
Wednesday
Moderate rain
54.4°F/49°F
4/2
Thursday
Patchy rain nearby
57°F/40.9°F
4/3
Friday
Sunny
65.1°F/38.6°F
4/4
Saturday
Moderate rain
62.8°F/47.3°F
4/5
Sunday
Patchy rain nearby
69.4°F/49.2°F
4/6
Monday
Sunny
69.7°F/49°F
4/7
Tuesday
Sunny
61.2°F/43°F
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