SeasonMapKaruizawa weather in May
Japan
May in Karuizawa: nice, rainy, with muggy air — one of the best months to visit.
#1 of 12 months in Karuizawa · #759 of 1383 destinations to visit in May · comfort 79/100 (tier B)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Karuizawa in May
Karuizawa's forum calls May one of the most pleasant months — its elevation keeps it noticeably cooler than Tokyo, with a day-to-night temperature swing of around 10°C that catches some visitors out. Regulars recommend layers for exactly that reason, plus a rain jacket just in case, and flag the first week of May (Golden Week) as considerably busier than the rest of the month.
Add your own note from Karuizawa's card on the map.
Karuizawa climate normals — May
| Daytime high | 19°C / 66°F | 😎 nice |
|---|---|---|
| Nighttime low | 6°C / 42°F | |
| Feels like (high) | 19°C / 66°F | |
| Rainfall | 145 mm / 5.7 in | 🌧 rainy |
| Rainy days | 16 days | |
| Humidity | 75% | 💦 very humid |
| Dew point | 8°C / 47°F | |
| Sunshine | 9.4 h/day | |
| Daylight | 14.1 h | |
| Wind | 10 km/h / 6 mph | |
| Snowfall | 0.4 cm / 0.2 in | |
| Air quality (US AQI) | 51 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Karuizawa in May
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusyGolden Week in Japan(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Karuizawa's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Best weatherKaruizawa's best weather comes in May, June and September — separate windows, not one continuous season.
Best weatherFair weatherToughest weather
Nearby, and something's on
Within 300 km of Karuizawa — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Karuizawa?
Karuizawa in May — FAQ
- Is May a good time to visit Karuizawa?
- May in Karuizawa: nice, rainy, with muggy air — one of the best months to visit. It ranks #1 of 12 months for Karuizawa on SeasonMap's comfort score (79/100).
- What is the weather like in Karuizawa in May?
- In May, Karuizawa averages a daily high of 18.8°C and a low of 5.5°C, with about 145.1 mm of rain over roughly 16 rainy days.
- What is the air quality in Karuizawa in May?
- Karuizawa has a mean US Air Quality Index of about 51 in May.
Other months in Karuizawa
Compare Karuizawa in May
Warmer or cooler than Karuizawa in May
Similar destinations in East Asia — May
Within 300 km: Matsumoto's Kamikochi open season around 17 Apr – 15 Nov, and Fujikawaguchiko's Fuji Shibazakura Festival around 11 Apr – 25 May.