US Napa Valley · Autumn

Napa Valley in September
what's the weather like?

September is one of the best times to visit Napa Valley.

Open-Meteo · 10 years · 12 months compared · 38.50°N 122.27°W
30°CMax temperature
4%Rainy days
12.0hSunshine / day

Napa Valley weather in September

✅ Good
🌡️ Temperature min / max
14°C – 30°C
🌧 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)

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°C.

🌧 Rain : ░░░░░░░░░░ 4%
🌡 Temperature : ████████░░ 30°C
☀️ Sunshine : █████████░ 12.0h/d

Our take: September is a good time to visit Napa Valley. June remains slightly better (+0.5 pts).

Napa Valley in September by trip type

What to expect in September

🎯 Peak season — book ahead for best rates. Accommodation prices at their highest Autumn in Napa Valley is often underrated: 30°C, 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.

All months for Napa Valley

Month-by-month comparison

MonthMin °CMax °CRain %Precip mmSun h/dScore
⛅ January5°C13°C35%4.88.3h5.1/10
⛅ February5°C14°C25%4.410.0h7.0/10
⛅ March6°C15°C36%3.611.0h7.0/10
🌤️ April8°C20°C16%1.012.4h7.9/10
☀️ May10°C25°C10%0.713.9h9.2/10
☀️ June13°C30°C2%0.114.1h9.4/10
☀️ July14°C33°C0%0.014.0h8.4/10
☀️ August15°C33°C0%0.013.1h8.2/10
☀️ September14°C30°C4%0.212.0h8.9/10
☀️ October11°C25°C11%1.410.3h8.5/10
⛅ November7°C17°C20%2.39.6h7.1/10
⛅ December5°C13°C32%4.08.0h5.3/10
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 30°C, 4% rainy days and 12.0h of sunshine per day. Overall weather score: 8.9/10. See methodology →

September vs June (best month)

The best month is June (score 9.4/10). Difference:

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 30°C, 12.0h of sunshine and 4% rain, conditions are very favourable.
Is it too hot in Napa Valley in September?
Temperatures reach 30°C. It's intense but manageable with sunscreen and water. Sunshine: 12.0h/day.

Find a place to stay in Napa Valley

Find places to stay in Napa Valley in September Search on Hotels.com

Activities and tours in Napa Valley

Guided tours, skip-the-line tickets and local experiences. Browse activities on GetYourGuide

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📅 Live forecast — next 12 months

Real-time data with ECMWF seasonal corrections · updated daily

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