Mountain town in Wakayama, Japan
Koyasan weather by month and the best time to visit
When to go to Koyasan
Late April, May and Oct–Nov are mild, with autumn color at its peak in November. Summer is cool but busy; winter is cold with snow and is quiet.
Koyasan weather by month
Average daily high, rainfall and conditions.
- Jan4°77 mm
- Feb5°95 mm
- Mar9°140 mm
- Apr14°173 mm
- May19°204 mm
- Jun22°269 mm
- Jul26°262 mm
- Aug27°246 mm
- Sep23°304 mm
- Oct18°253 mm
- Nov12°121 mm
- Dec6°86 mm
Monthly averages
| Month | High | Low | Rain | Humidity | Conditions |
|---|---|---|---|---|---|
| January | 4°C38°F | -4°C25°F | 77 mm | 87% | Cold |
| February | 5°C42°F | -3°C26°F | 95 mm | 85% | Cold |
| March | 9°C49°F | -1°C31°F | 140 mm | 82% | Cold |
| April | 14°C58°F | 4°C39°F | 173 mm | 81% | Rainy |
| May | 19°C66°F | 9°C49°F | 204 mm | 81% | Rainy |
| June | 22°C72°F | 14°C57°F | 269 mm | 85% | Rainy |
| July | 26°C78°F | 18°C65°F | 262 mm | 86% | Rainy |
| August | 27°C80°F | 19°C66°F | 246 mm | 85% | Rainy |
| September | 23°C74°F | 15°C60°F | 304 mm | 86% | Very wet |
| October | 18°C64°F | 9°C49°F | 253 mm | 86% | Rainy |
| November | 12°C54°F | 4°C39°F | 121 mm | 86% | Cool |
| December | 6°C43°F | -2°C29°F | 86 mm | 87% | Cold |
Best months across Japan
| Place | Best months | Warmest month |
|---|---|---|
| Tokyo | Mar–May, Oct–Nov | Aug (30°C) |
| Kyoto | Mar–May, Oct–Nov | Aug (31°C) |
| Osaka | Mar–May, Oct–Nov | Aug (32°C) |
| Hiroshima | Mar–May, Oct–Nov | Aug (32°C) |
| Nara | Mar–May, Oct–Nov | Aug (31°C) |
| Sapporo | Feb, Jun–Sep | Aug (26°C) |
| Okinawa | Apr–Jun, Oct–Nov | Aug (30°C) |
| Hakone | Apr–May, Oct–Dec | Aug (24°C) |
| Fukuoka | Mar–May, Oct–Nov | Aug (32°C) |
| Kawaguchiko | Oct–Feb | Aug (26°C) |
| Niseko | Jul–Aug, Dec–Mar | Aug (24°C) |
| Yokohama | Mar–May, Oct–Nov | Aug (31°C) |
| Kanazawa | Apr–May, Oct–Nov | Aug (31°C) |
| Takayama | Apr–May, Oct–Nov | Aug (29°C) |
| Nagoya | Mar–May, Oct–Nov | Aug (31°C) |
| Nikko | May, Jul–Aug, Oct–Nov | Aug (28°C) |
| Kamakura | Mar–May, Oct–Nov | Aug (31°C) |
| Kobe | Mar–May, Oct–Nov | Aug (30°C) |
| Hakuba | Jan–Feb, Jul–Sep | Aug (28°C) |
| Ishigaki | Apr–May, Jul, Sep–Oct | Jul (29°C) |
| Nagasaki | Mar–May, Oct–Nov | Aug (31°C) |
| Shirakawa-go | Feb, May, Oct–Nov | Aug (28°C) |
| Miyakojima | Apr–Jun, Sep–Oct | Jul (29°C) |
| Hakodate | Jun–Oct | Aug (25°C) |
| Otaru | Feb, Jun–Sep | Aug (26°C) |
| Beppu | Mar–May, Oct–Nov | Aug (31°C) |
| Matsumoto | Apr–May, Sep–Nov | Aug (29°C) |
| Koyasan | Apr–May, Oct–Nov | Aug (27°C) |
| Furano | Jan–Feb, Jul–Aug | Aug (25°C) |
| Sendai | Apr–May, Sep–Nov | Aug (29°C) |
Quick answers
What is the best month to visit Koyasan?
Apr–May, Oct–Nov. Late April, May and Oct–Nov are mild, with autumn color at its peak in November. Summer is cool but busy; winter is cold with snow and is quiet.
When is the rainy season in Koyasan?
Rain peaks in September with about 304 mm. Months with 150 mm or more: Apr–Oct.
What is the hottest month in Koyasan?
August, with average highs of 27°C (80°F).
How cold does Koyasan get?
The coolest nights are in January, averaging -4°C (25°F).
More about Koyasan
Going to Koyasan solo?
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Sources
- NASA POWER climatology (2001–2020)
- Koyasan Shukubo Association
- Koyasan Tourist Association
- Nankai Electric Railway
Climate averages are modelled from NASA POWER (MERRA-2) for 2001–2020 at about 50 km resolution, so coasts and valleys can differ a little. Temperatures are adjusted by 2°C for the city's elevation. Compiled and reviewed by SoloSquare. How we compile and score this. Spotted something out of date? Tell us.