Karuizawa Weather in August
August in Karuizawa brings high temperatures, with highs of 28°C (82°F) and nights dropping to 19°C (66°F). The rainy season is in full swing this month, so frequent downpours are part of the picture.
Rainfall in Karuizawa in August
Karuizawa is in the rainy season in August, with rain on around 20 days and an average of 211 mm (8.3 in). Rainy season showers tend to be fairly substantial. A good rain jacket or umbrella is worth having with you most days.
Temperature in Karuizawa in August
August in Karuizawa brings high temperatures, with highs of 28°C (82°F) and nights around 19°C (66°F). The month of August belongs to the summer season. This kind of day-to-night contrast is typical for this time of year. With lows of 19°C (66°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest. This is typically the warmest month of the year, so light summer clothing is a good idea.
Sunshine in Karuizawa in August
The city usually sees around 206 hours of sunlight, indicating many sunny days despite it being the rainy season.If you prefer dry days with pleasant temperatures, May typically offers the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Japan, check out our Karuizawa's climate page.
Karuizawa Temperature in August
Min Temperature
19°C (66°F)
Max Temperature
28°C (82°F)
Chance of Rain
67%
Precipitation
211 mm (8.3 in)
Rainy days
20 days
Humidity
72% *
Sunshine
206 hours *
Percentage Sunshine
*
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Karuizawa typically stay consistent throughout August, with daily highs averaging around 28°C (82°F). Nights are pleasant, with lows around 19°C (66°F).
Average temperatures in August
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in August
Historical weather for Karuizawa in August
Browse day-by-day weather records for Karuizawa spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Karuizawa historical weather extremes in August
Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in Karuizawa.
- Karuizawa recorded its highest August temperature of 36°C (97°F) on August 6, 2002.
- On August 27, 1996, Karuizawa saw its coldest August day with temperatures maxing out at 14°C (57°F).
- The coldest night in August in Karuizawa was on August 18, 2018, with a minimum of 9°C (48°F).
Best Places in Japan in August
Find out more about the weather in Japan and which places have the best travel conditions in this month. See all of Japan in August →
perfect weather
pleasant
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What to Wear in Karuizawa in August
Warm but pleasant conditions in Karuizawa in August. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. It's going to pour! Pack a good poncho and prepare for very wet conditions. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Karuizawa in August
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Japan, check out our Karuizawa's climate page.
Temperature Rainfall Sunshine Humidity
See the full Karuizawa climate overview or explore weather in Japan.
