Napa weather in May
May in Napa: warm, dry, with clean air — one of the best months to visit.
#2 of 12 months in Napa · #12 of 604 destinations to visit in May · comfort 94/100 (tier S)
Updated June 2026 · climate normals from ERA5 reanalysis
Napa climate normals — May
| Daytime high | 26°C / 79°F | 🌤 warm |
|---|---|---|
| Nighttime low | 12°C / 53°F | |
| Feels like (high) | 25°C / 77°F | |
| Rainfall | 23 mm / 0.9 in | ☀️ dry |
| Rainy days | 3 days | |
| Humidity | 61% | 💧 humid |
| Dew point | 8°C / 47°F | |
| Sunshine | 12.4 h/day | |
| Daylight | 14.3 h | |
| Wind | 17 km/h / 11 mph | |
| Air quality (US AQI) | 36 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Napa in May — FAQ
- Is May a good time to visit Napa?
- May in Napa: warm, dry, with clean air — one of the best months to visit. It ranks #2 of 12 months for Napa on SeasonMap's comfort score (94/100).
- What is the weather like in Napa in May?
- In May, Napa averages a daily high of 26.1°C and a low of 11.8°C, with about 22.6 mm of rain over roughly 3.4 rainy days.
- What is the air quality in Napa in May?
- Napa has a mean US Air Quality Index of about 36 in May.