Weather in Nagano for September 2025
Until now, September 2025 in Nagano has been nearly identical to the historical average, with a temperature of 27.8 °C (showing only a slight deviation of 0.5 °C).
Expect cooler weather in the next days in Nagano with the forecast suggesting a temperature of 23.9 °C, lower than the historical average.
In general, the average temperature in Nagano at the beginning of September is 27.3 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 25.1 °C by the end of September.
Nagano experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 217.7 mm.
Is September a good time to visit Nagano? check out the best time to travel to Nagano page.
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Nagano Weather September
What’s the Weather Like in Nagano This September?
Temperatures trend during September in Nagano
September weather in Nagano day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Patchy rain possible | 29° /16° | 6 mm | 6 | |
| 2 Sept. |  Moderate rain at times | 27° /16° | 11.3 mm | 6 | |
| 3 Sept. | Light rain shower | 27° /15° | 11.2 mm | 6 | |
| 4 Sept. | Moderate or heavy rain shower | 27° /15° | 10.8 mm | 6 | |
| 5 Sept. | Moderate or heavy rain shower | 27° /15° | 19 mm | 6 | |
| 6 Sept. | Moderate or heavy rain shower | 27° /14° | 6.5 mm | 6 | |
| 7 Sept. | Patchy rain possible | 27° /13° | 1.1 mm | 6 | |
| 8 Sept. | Moderate or heavy rain shower | 24° /15° | 19.2 mm | 5 | |
| 9 Sept. | Light rain shower | 28° /15° | 9.8 mm | 6 | |
| 10 Sept. | Patchy rain possible | 29° /16° | 5.5 mm | 6 | |
| 11 Sept. | Light rain shower | 27° /15° | 7.5 mm | 6 | |
| 12 Sept. | Light rain shower | 28° /15° | 1.9 mm | 7 | |
| 13 Sept. | Light rain shower | 28° /15° | 3.6 mm | 6 | |
| 14 Sept. | Patchy rain possible | 29° /15° | 0.7 mm | 7 | |
| 15 Sept. | Patchy rain possible | 28° /17° | 3.2 mm | 1.8 | |
| 16 Sept. | Patchy rain possible | 31° /17° | 0.8 mm | 1.9 | |
| 17 Sept. | Patchy rain possible | 31° /16° | 3.4 mm | 1.8 | |
| 18 Sept. |  Moderate rain | 24° /16° | 7.3 mm | 0.7 | |
| 19 Sept. |  Heavy rain | 16° /15° | 47.4 mm | 4 | |
| 20 Sept. | Moderate rain | 17° /15° | 5.5 mm | 4 | |
| 21 Sept. | Patchy rain possible | 16° /14° | 3.4 mm | 3 | |
| 22 Sept. | Patchy rain possible | 22° /13° | 0.4 mm | 4 | |
| 23 Sept. | Patchy rain possible | 24° /14° | 0.6 mm | 4 | |
| 24 Sept. | Patchy rain possible | 24° /14° | 0.2 mm | 4 | |
| 25 Sept. | Patchy rain possible | 24° /16° | 1.6 mm | 4 | |
| 26 Sept. |  Partly cloudy | 30° /14° | 0 mm | 6 | |
| 27 Sept. | Patchy rain possible | 26° /17° | 1.3 mm | 4 | |
| 28 Sept. | Patchy rain possible | 22° /13° | 0.1 mm | 4 | |
| 29 Sept. | Partly cloudy | 24° /10° | 0.3 mm | 6 | |
| 30 Sept. | Moderate rain at times | 26° /11° | 0.7 mm | 6 | |
| Next | |||||
Nagano weather in September vs August vs October
| August | September | October | |
|---|---|---|---|
| Weather | Patchy rain possible | Patchy rain possible | Patchy rain possible |
| Temperatures | 30°/18° | 26°/14° | 18°/6° |
| Rainfall | 264 mm | 218 mm | 152 mm |
| Wind | 8.5 km/h | 8 km/h | 8.8 km/h |
| Humidity | 82% | 84% | 80% |
| Rainy days | 29 days | 26 days | 26 days |
| Dry days | 2 days | 4 days | 5 days |
Planning a trip to Nagano? Discover the best time to visit
Nagano in September - FAQ
What to pack to Nagano in September?
As you prepare for your trip to Nagano 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 Nagano, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Lightweight Clothing: T-shirts, blouses, shorts, skirts
- 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
- Personal Items
- Sunscreen: High SPF for sunny destinations
- Lip Balm with SPF: To protect against chapped lips
September rainfall patterns in Nagano
UV exposure in Nagano during September
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Where is Nagano?Get accurate weather forecasts for Nagano, located at latitude 36.65 and longitude 138.183. Stay updated with localized weather information tailored for Nagano.