When to go · Karuizawa
Karuizawa in September
Mixed month. Outside the best window (May–Jun, Oct–Nov). Across Japan: Still hot; typhoon peak can cancel flights and ferries for a day or two.
Key facts
- Verdict
- Mixed
- Temperature
- 21°C (70°F)70°F (21°C) / 14°C (57°F)57°F (14°C)
- average high / low
- Rain days
- 13
- Crowds
- Medium
- Japan overall
- Prices
- Medium
- Japan overall
Verdict
Outside the best window (May–Jun, Oct–Nov). Across Japan: Still hot; typhoon peak can cancel flights and ferries for a day or two.
Is another month better than September?
September is rated mixed. These months rate higher:
Weather in September
- KaruizawaHighs around 21 °C (70 °F), lows around 14 °C (57 °F), rain on about 13 daysHighs around 70 °F (21 °C), lows around 57 °F (14 °C), rain on about 13 days
Crowds and prices
- Crowds · Japan overall
- Medium
- Prices · Japan overall
- Medium
Japan overall: Still hot; typhoon peak can cancel flights and ferries for a day or two.
Compare two months
Weather, crowds and prices for any two months in Karuizawa, side by side.
Verdict
Sep: Mixed
May: Great (better)
Daytime high
Sep: 21 °C (70 °F)70 °F (21 °C)
May: 17 °C (63 °F)63 °F (17 °C)
Night low
Sep: 14 °C (57 °F)57 °F (14 °C)
May: 8 °C (46 °F)46 °F (8 °C)
Rain days
Sep: 13
May: 11 (better)
Crowds
Sep: Medium
May: Medium
Prices
Sep: Medium
May: Medium
Festivals listed
Sep: 0
May: 1
September: Outside the best window (May–Jun, Oct–Nov). Across Japan: Still hot; typhoon peak can cancel flights and ferries for a day or two.
May: Inside Karuizawa's best window: May–Jun, Oct–Nov.
Karuizawa: figures are long-term averages from this guide, not a forecast.
What to pack
- A rain jacket or umbrella and shoes that dry fast