Our verdict
The best time to visit Karuizawa is September
In summer, the temperature in Karuizawa can rise as high as 29℃ (84℉). The coldest it usually gets in winter-time in Karuizawa is around -11℃ (13℉).
The sun stays up the longest in Karuizawa in May, so you’ll get the most out of your daytime activities if you visit around this time. July sees the most amount of rain in a month if you’re ok with chancing getting drenched, so if you’re looking to stay dry, visit in December instead.
For more information about when to travel to Karuizawa, the monthly weather breakdown and the best information and tools to book your trip, continue reading below.
Quick links: Fast facts / Seasons / Average temperatures / Monthly climate / FAQs / Map
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Karuizawa seasons
Before you continue, it’s important to know when the seasons are in Karuizawa as they might be different to yours depending on where in the world you’re travelling from. Karuizawa is in the Northern Hemisphere, so the seasons fall during these months:
| Season | Months |
|---|---|
| Summer | June to August |
| Autumn/fall | September to November |
| Winter | December to February |
| Spring | March to May |
Average temperatures in Karuizawa
If the temperature is a big factor for you to help you decide when to visit, the chart below shows the average minimum and maximum temperatures in Karuizawa for each month side-by-side so you can easily see the difference in weather throughout the year. To see the temperatures in both Celsius (°C) and Fahrenheit (°F), hover or tap the shaded boxes on the graph.
Karuizawa climate by month
If you already have a rough idea about which months you might want to travel, the section below shows a detailed breakdown of the climate in Karuizawa for each month so you can see if it all suits your wants and needs. Scroll down, or use the quick menu below to jump to your preferred month.
Jump to:
Karuizawa in January
- Average temperature: -4℃ (24℉)
- Average high temperature: -0℃ (31℉)
- Average low temperature: -8℃ (17℉)
- Average humidity: 83%
- Average sunny days: 5 days
- Average rainfall: 52mm (2") over 13 days
- Average snow days: 24 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in January, make sure you pack a thick snow/winter jacket, thermals and some extra layers as it's always very cold.
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Karuizawa in February
- Average temperature: -4℃ (26℉)
- Average high temperature: 1℃ (34℉)
- Average low temperature: -8℃ (18℉)
- Average humidity: 85%
- Average sunny days: 5 days
- Average rainfall: 45mm (2") over 13 days
- Average snow days: 21 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in February, make sure you pack a thick snow/winter jacket, thermals and some extra layers as it's always very cold.
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Karuizawa in March
- Average temperature: 1℃ (34℉)
- Average high temperature: 6℃ (42℉)
- Average low temperature: -4℃ (25℉)
- Average humidity: 79%
- Average sunny days: 7 days
- Average rainfall: 70mm (3") over 16 days
- Average snow days: 18 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in March, make sure you pack a thick snow/winter jacket, thermals and some extra layers as it's always very cold.
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Karuizawa in April
- Average temperature: 7℃ (44℉)
- Average high temperature: 12℃ (53℉)
- Average low temperature: 2℃ (35℉)
- Average humidity: 75%
- Average sunny days: 8 days
- Average rainfall: 83mm (3") over 18 days
- Average snow days: 5 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in April, make sure you pack a thick snow/winter jacket, thermals and some extra layers as it's always very cold.
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Karuizawa in May
- Average temperature: 13℃ (55℉)
- Average high temperature: 18℃ (65℉)
- Average low temperature: 7℃ (45℉)
- Average humidity: 75%
- Average sunny days: 10 days
- Average rainfall: 88mm (3") over 19 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in May, make sure you pack a warm jacket or coat.
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Karuizawa in June
- Average temperature: 16℃ (61℉)
- Average high temperature: 21℃ (70℉)
- Average low temperature: 11℃ (52℉)
- Average humidity: 83%
- Average sunny days: 4 days
- Average rainfall: 123mm (5") over 24 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in June, make sure you pack a coat or jumper for the evenings and some light clothes for the daytime.
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Karuizawa in July
- Average temperature: 20℃ (68℉)
- Average high temperature: 25℃ (77℉)
- Average low temperature: 16℃ (61℉)
- Average humidity: 86%
- Average sunny days: 2 days
- Average rainfall: 177mm (7") over 27 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in July, make sure you pack t-shirts for the daytime and maybe a light jumper for the evenings as it cools down a bit.
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Karuizawa in August
- Average temperature: 21℃ (69℉)
- Average high temperature: 26℃ (79℉)
- Average low temperature: 17℃ (62℉)
- Average humidity: 85%
- Average sunny days: 2 days
- Average rainfall: 155mm (6") over 27 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in August, make sure you pack t-shirts for the daytime and maybe a light jumper for the evenings as it cools down a bit.
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Karuizawa in September
- Average temperature: 16℃ (61℉)
- Average high temperature: 21℃ (71℉)
- Average low temperature: 12℃ (54℉)
- Average humidity: 86%
- Average sunny days: 7 days
- Average rainfall: 111mm (4") over 20 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in September, make sure you pack a light jumper or hoodie for the evenings and some light clothes for the daytime.
Karuizawa in October
- Average temperature: 11℃ (52℉)
- Average high temperature: 16℃ (60℉)
- Average low temperature: 7℃ (45℉)
- Average humidity: 85%
- Average sunny days: 9 days
- Average rainfall: 148mm (6") over 18 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in October, make sure you pack a warm jacket or coat.
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Karuizawa in November
- Average temperature: 5℃ (41℉)
- Average high temperature: 10℃ (49℉)
- Average low temperature: 1℃ (34℉)
- Average humidity: 82%
- Average sunny days: 12 days
- Average rainfall: 49mm (2") over 15 days
- Average snow days: 5 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in November, make sure you pack a thick snow/winter jacket, thermals and some extra layers as it's always very cold.
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Karuizawa in December
- Average temperature: -1℃ (30℉)
- Average high temperature: 3℃ (37℉)
- Average low temperature: -4℃ (24℉)
- Average humidity: 81%
- Average sunny days: 7 days
- Average rainfall: 43mm (2") over 15 days
- Average snow days: 19 days
of pure sunshine
of showers or rain
What to pack: If you’re heading to Karuizawa in December, make sure you pack a thick snow/winter jacket, thermals and some extra layers as it's always very cold.
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