When to visit Sun Valley?
The decision rests on several criteria. Climate score, tourist crowds and feasible activities.
What you grasp in 5 seconds
Sun Valley offers 4 comfortable months, without any month really to avoid. The gap stays moderate: 9.3 in July vs 4.0 in December.
What to check next
Your tolerance for crowds and budget. The best months concentrate tourist saturation and higher prices. Shoulder seasons offer a good compromise.
Next action
Scroll down to the detailed table to compare month by month, then open the page of the month that interests you.
How we calculate the score
For mountain destinations, we calculate two scores per month — skiing and hiking — and display the higher of the two.
- 40% snow cover (slope T° corrected by lapse rate -6.5°C/1000m)
- 40% winter thermal comfort (-5 to 5°C optimal)
- 20% sunshine
- Off-season penalty: ×0.70 adjacent months · ×0.35 outside season
- 40% temperature (10–22°C optimal)
- 40% rain (frequency + daily intensity)
- 20% sunshine
Source : ERA5 · Open-Meteo · 10 years (2016–2025) · Full methodology →
Compare all 12 months
Month-by-month details: temperature, rain, sunshine, score and verdict.
| Month | T° min | T° max | Rain % | mm/day | Sun | Score | Verdict |
|---|---|---|---|---|---|---|---|
| 🌥️ January → | -11°C | 0°C | 24% | 1.9mm | 5.1h | 4.0/10 | Decent period |
| 🌥️ February → | -11°C | 0°C | 27% | 2.6mm | 5.6h | 4.0/10 | Decent period |
| 🌥️ March → | -8°C | 3°C | 26% | 2.2mm | 6.4h | 4.0/10 | Decent period |
| 🌥️ April → | -4°C | 8°C | 20% | 1.3mm | 7.8h | 4.2/10 | Decent period |
| 🌥️ May → | 0°C | 14°C | 25% | 1.8mm | 7.9h | 4.4/10 | Decent period |
| ☀️ June → | 5°C | 21°C | 17% | 1.1mm | 9.4h | 8.2/10 | Best period |
| ☀️ July → | 10°C | 28°C | 8% | 0.4mm | 9.9h | 9.3/10 | Best period |
| ☀️ August → | 10°C | 27°C | 12% | 0.8mm | 8.7h | 8.9/10 | Best period |
| ☀️ September → | 5°C | 21°C | 15% | 1.0mm | 7.5h | 8.0/10 | Best period |
| 🌥️ October → | -1°C | 12°C | 17% | 1.4mm | 6.6h | 4.4/10 | Decent period |
| 🌥️ November → | -6°C | 5°C | 19% | 1.4mm | 5.6h | 4.1/10 | Decent period |
| 🌥️ December → | -12°C | 0°C | 24% | 2.2mm | 4.9h | 4.0/10 | Decent period |
Annual temperatures — Sun Valley
Min/max temperature curves observed over the past 10 years (ERA5). Shows climate stability and trend.
For your trip
A few angles depending on what kind of trip you are planning.
Plan your trip
Hotels at their lowest outside peak season, highest on comfortable months. Shoulder seasons offer a good price/climate compromise.
🎟️ Activities & tours · Sun Valley
GetYourGuide selection · free cancellation
What you need to know before you go
Three angles: the country (language, currency, safety, budget), the year-round climate, and the specifics of a mountain stay.
Country · United States
🌡️ Climate
🏔️ Mountain stay
Related destinations & guides
If this destination doesn't fit your dates, here are alternatives and guides.
Similar climate destinations
Nearby destinations
Big White Guides & rankings
Where is Sun Valley ?
Global position + regional geographic context.