San Francisco weather in May
May in San Francisco: nice, dry, with clean air — an excellent time to visit.
#6 of 12 months in San Francisco · #114 of 604 destinations to visit in May · comfort 89/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
San Francisco climate normals — May
| Daytime high | 20°C / 67°F | 😎 nice |
|---|---|---|
| Nighttime low | 11°C / 51°F | |
| Feels like (high) | 19°C / 66°F | |
| Rainfall | 20 mm / 0.8 in | ☀️ dry |
| Rainy days | 3 days | |
| Humidity | 72% | 💧 humid |
| Dew point | 9°C / 47°F | |
| Sunshine | 12.5 h/day | |
| Daylight | 14.2 h | |
| Wind | 20 km/h / 12 mph | |
| Air quality (US AQI) | 42 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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San Francisco in May — FAQ
- Is May a good time to visit San Francisco?
- May in San Francisco: nice, dry, with clean air — an excellent time to visit. It ranks #6 of 12 months for San Francisco on SeasonMap's comfort score (89/100).
- What is the weather like in San Francisco in May?
- In May, San Francisco averages a daily high of 19.5°C and a low of 10.6°C, with about 20.4 mm of rain over roughly 3 rainy days.
- What is the air quality in San Francisco in May?
- San Francisco has a mean US Air Quality Index of about 42 in May.