This trip gave us a truly unique and visually stunning experience! It really made me realize how crucial it is to have a great tour guide! They not only explained the local customs and history but also introduced us to delicious local cuisine. They were also incredibly attentive, reminding us of important details to consider due to the changeable weather – a lifesaver for lazy travelers like us! Our driver, Hanazawa, was also exceptional! Not only was his driving skill impeccable, but he also politely yielded to other cars on mountain roads multiple times! This was a complete surprise! He was so kind! He even helped us find beautiful scenery to capture wonderful memories! A highly recommended itinerary! Those who enjoy exploring unique attractions should definitely check it out!
Anonymous User
Family
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
2/15
Sunday
Partly Cloudy
61.2°F/40.8°F
2/16
Monday
Patchy rain nearby
46.8°F/31.8°F
2/17
Tuesday
Sunny
50.7°F/29.5°F
2/18
Wednesday
Partly Cloudy
49.3°F/31.3°F
2/19
Thursday
Sunny
50.5°F/30.7°F
2/20
Friday
Partly Cloudy
55.8°F/34.4°F
2/21
Saturday
Patchy rain nearby
57.7°F/40°F
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