When to go · Sun Valley
Sun Valley in September
Great month. Inside Sun Valley's best window: Jan–Mar (ski), Jul–Sep (hike, bike, fish).
Key facts
- Verdict
- Great
- Temperature
- 23°C (73°F)73°F (23°C) / 4°C (39°F)39°F (4°C)
- average high / low
- Rain days
- 5
- Crowds
- Medium
- United States overall
- Prices
- Medium
- United States overall
Verdict
Inside Sun Valley's best window: Jan–Mar (ski), Jul–Sep (hike, bike, fish).
Is another month better than September?
No other month rates higher than September for Sun Valley in this guide.
Weather in September
- Sun ValleyHighs around 23 °C (73 °F), lows around 4 °C (39 °F), rain on about 5 daysHighs around 73 °F (23 °C), lows around 39 °F (4 °C), rain on about 5 days
Festivals and holidays
Dates as our data lists them. Moving holidays (lunar and Islamic calendars, Easter) shift every year: check the date for your year before you build a trip on it.
Labor Day big impact
1st Monday of September · United States
End of summer; last big road-trip weekend.
Crowds and prices
- Crowds · United States overall
- Medium
- Prices · United States overall
- Medium
United States overall: After Labor Day the crowds drop and parks stay open; Florida and the Gulf are at hurricane peak.
Compare two months
Weather, crowds and prices for any two months in Sun Valley, side by side.
Verdict
Sep: Great
Jan: Great
Daytime high
Sep: 23 °C (73 °F)73 °F (23 °C)
Jan: 0 °C (32 °F)32 °F (0 °C)
Night low
Sep: 4 °C (39 °F)39 °F (4 °C)
Jan: -12 °C (10 °F)10 °F (-12 °C)
Rain days
Sep: 5 (better)
Jan: 9
Crowds
Sep: Medium
Jan: Low
Prices
Sep: Medium
Jan: Low
Festivals listed
Sep: 1
Jan: 0
September: Inside Sun Valley's best window: Jan–Mar (ski), Jul–Sep (hike, bike, fish).
January: Inside Sun Valley's best window: Jan–Mar (ski), Jul–Sep (hike, bike, fish).
Sun Valley: figures are long-term averages from this guide, not a forecast.
What to pack
- A warm coat, hat and gloves for mornings and evenings