Karuizawa
September
Weather in Karuizawa for September 2025
Your guide to Karuizawa weather in September - trends and predictions
In general, the average temperature in Karuizawa at the beginning of September is 23.6 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 17.9 °C by the end of September.
Karuizawa experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 129.9 mm.
Is September a good time to visit Karuizawa? check out the best time to travel to Karuizawa page.
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Temperatures
Rain 🌧️
More
4
Dry days
26
Rainy days
0
Snow days
22°/14°
Temperatures
8 km/h
Avg max wind
86 %
Avg humidity
Karuizawa in September average weather
Move between months or click on a day
| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  24° | 2 25° | 3 19° | 4 21° | 5 24° | 6 25° | 7 27° |
| 8 23° | 9 22° | 10 24° | 11 25° | 12 24° | 13 25° | 14  24° |
| 15 23° | 16 22° | 17 28° | 18 28° | 19 22° | 20 26° | 21 20° |
| 22 23° | 23 20° | 24  14° | 25  16° | 26 22° | 27 21° | 28 20° |
| 29 16° | 30 16° |
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Access Karuizawa weather forecasts with a simple click. Select any date for comprehensive insights on temperature, rainfall, and wind conditions.
Temperatures trend during September in Karuizawa
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Patchy rain possible | 24° /16° | 1.2 mm | 5 | |
| 2 Sept. | Patchy rain possible | 25° /16° | 3.2 mm | 6 | |
| 3 Sept. | Light rain shower | 19° /15° | 16.8 mm | 4 | |
| 4 Sept. | Patchy rain possible | 21° /11° | 0.2 mm | 5 | |
| 5 Sept. | Light rain shower | 24° /13° | 0.9 mm | 5 | |
| 6 Sept. | Patchy rain possible | 25° /14° | 0.1 mm | 6 | |
| 7 Sept. | Patchy rain possible | 27° /15° | 3.5 mm | 6 | |
| 8 Sept. | Light rain shower | 23° /16° | 20.2 mm | 5 | |
| 9 Sept. | Light rain shower | 22° /16° | 5.8 mm | 5 | |
| 10 Sept. | Light rain shower | 24° /15° | 7.2 mm | 5 | |
| 11 Sept. | Light rain shower | 25° /15° | 9.5 mm | 6 | |
| 12 Sept. | Light rain shower | 24° /16° | 5.2 mm | 5 | |
| 13 Sept. | Light rain shower | 25° /16° | 12.7 mm | 6 | |
| 14 Sept. | Patchy light drizzle | 24° /16° | 1.8 mm | 5 | |
| 15 Sept. | Light rain shower | 23° /16° | 3.9 mm | 5 | |
| 16 Sept. | Light rain shower | 22° /16° | 4.3 mm | 5 | |
| 17 Sept. | Light rain shower | 28° /16° | 3.7 mm | 6 | |
| 18 Sept. | Light rain shower | 28° /19° | 5.2 mm | 6 | |
| 19 Sept. | Light rain shower | 22° /15° | 4 mm | 5 | |
| 20 Sept. | Patchy rain possible | 26° /15° | 0.2 mm | 6 | |
| 21 Sept. | Patchy light drizzle | 20° /16° | 1.1 mm | 5 | |
| 22 Sept. | Light rain shower | 23° /14° | 6 mm | 5 | |
| 23 Sept. | Patchy rain possible | 20° /10° | 1.5 mm | 5 | |
| 24 Sept. | Fog | 14° /8° | 0.6 mm | 3 | |
| 25 Sept. | Partly cloudy | 16° /6° | 0 mm | 5 | |
| 26 Sept. | Patchy rain possible | 22° /12° | 2.2 mm | 5 | |
| 27 Sept. | Light rain shower | 21° /13° | 1.4 mm | 5 | |
| 28 Sept. | Light rain shower | 20° /13° | 4.8 mm | 5 | |
| 29 Sept. | Light rain shower | 16° /13° | 2.3 mm | 4 | |
| 30 Sept. | Fog | 16° /12° | 0.6 mm | 4 | |
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Important Notice
Our weather forecast for Karuizawa in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Karuizawa forecast closer to your planned date for the most up-to-date weather information.
Karuizawa in September - FAQ
What are the expected maximum and minimum temperatures in Karuizawa during September?
Enjoy moderate daytime temperatures of up to 22° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Karuizawa during September?
Significant rainfall exceeding 129.9 mm is expected in Karuizawa during September, occurring over more than 26 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Karuizawa during September?
The average wind speed in Karuizawa during September is 8 km/h, suggesting breezy to windy conditions, depending on your activities.
What to pack to Karuizawa in September?
As you prepare for your trip to Karuizawa in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in Karuizawa, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Warm Clothing: Sweaters, hoodies, long pants
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm weather
- Scarves: To protect you from the cold wind
- Gloves/Mittens: Essential for cold weather
- Warm Hats: Warm hats for insulation in cold weather
- Umbrellas/Raincoats: For rainy days
September rainfall patterns in Karuizawa
Explore the daily rainfall trends and prepare for Karuizawas September weather 💧
UV exposure in Karuizawa during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Karuizawa?Get accurate weather forecasts for Karuizawa, located at latitude 36.35 and longitude 138.633. Stay updated with localized weather information tailored for Karuizawa.
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