Napa Valley · AutumnMonth summary
Napa Valley weather in September
✅ Good
🌡️ Temperature min / max
57°F – 86°F
🌧 Rainy days
4% of days
☀️ Sunshine
12.0h per day on average
🌊 🌊 Season
Autumn
⭐ ⭐ Weather score
8.9/10
📅 📅 Best month
June (9.4/10)
Quick decision
Should you visit Napa Valley in September?
✅ Good
✅ Yes if: you're looking for maximum sunshine — 12.0h per day on average.
❌ No if: you struggle with heat — temperatures regularly exceed 30°F.
Our take: September is a good time to visit Napa Valley. June remains slightly better (+0.5 pts).
By trip type
Napa Valley in September by trip type
- 🏙️ 🏙️ City break / culture : ✅ Good
- 🚶 🚶 Outdoor activities : ✅ Good
- 🏖️ Beach / swimming : — No sea access
- 💰 💰 Budget : 💸 Peak season
Local context
What to expect in September
Autumn in Napa Valley is often underrated: 30°F, golden light and declining crowds. An interesting window. Rain is virtually absent (4% of days) — ideal for planning without a backup. A good balance between weather and crowds, even if June (9.4/10) remains theoretically better.
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All months for Napa Valley
Annual table
Month-by-month comparison
| Month | Min °F | Max °F | Rain % | Precip in | Sun h/d | Score |
|---|---|---|---|---|---|---|
| ⛅ January | 41°F | 55°F | 35% | 0.2in | 8.3h | 5.1/10 |
| ⛅ February | 41°F | 57°F | 25% | 0.2in | 10.0h | 7.0/10 |
| ⛅ March | 43°F | 59°F | 36% | 0.1in | 11.0h | 7.0/10 |
| 🌤️ April | 46°F | 68°F | 16% | 0.0in | 12.4h | 7.9/10 |
| ☀️ May | 50°F | 77°F | 10% | 0.0in | 13.9h | 9.2/10 |
| ☀️ June | 55°F | 86°F | 2% | 0.0in | 14.1h | 9.4/10 |
| ☀️ July | 57°F | 91°F | 0% | 0.0in | 14.0h | 8.4/10 |
| ☀️ August | 59°F | 91°F | 0% | 0.0in | 13.1h | 8.2/10 |
| ☀️ September | 57°F | 86°F | 4% | 0.0in | 12.0h | 8.9/10 |
| ☀️ October | 52°F | 77°F | 11% | 0.1in | 10.3h | 8.5/10 |
| ⛅ November | 45°F | 63°F | 20% | 0.1in | 9.6h | 7.1/10 |
| ⛅ December | 41°F | 55°F | 32% | 0.2in | 8.0h | 5.3/10 |
Ideal
Fair
Challenging climate
◀ Current month · Source Open-Meteo · 10 years
📊 Data source
Data based on 10 years of ERA5 records via Open-Meteo, with ECMWF seasonal adjustment. In September, Napa Valley averages 86°F, 4% rainy days and 12.0h of sunshine per day. Overall weather score: 8.9/10.
See methodology →
Comparison
September vs June (best month)
The best month is June (score 9.4/10). Difference:
- 🌡️ Max temperature : +0°F
- 🌧 Rainy days : -2%
- ☀️ Sunshine : +2.1h/day
FAQ
FAQ — Napa Valley in September
Is September a good time to visit Napa Valley?
September is an excellent time to visit Napa Valley (score 8.9/10). With 86°F, 12.0h of sunshine and 4% rain, conditions are very favourable.
Is it too hot in Napa Valley in September?
Temperatures reach 86°F. It's intense but manageable with sunscreen and water. Sunshine: 12.0h/day.
Accommodation
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Activities & tours
Activities and tours in Napa Valley
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