United States San Francisco Weather in May — Climate Guide
May in San Francisco is Excellent
San Francisco Weather in May — Quick Answer
As of 2026- Avg temp
- 19° / 12°
- Rainfall
- 18mm · 3 days
- Crowds
- Busy
As of 2026, San Francisco in May averages a high of 19°C and low of 12°C with 18mm of rain over about 3 days. Late spring — high 19°C, low 12°C. Light layers, sunscreen. Fog beginning some mornings; clear afternoons.
May is Excellent for San Francisco.
May is peak spring — sunny, dry, mild. Bay to Breakers (3rd Sunday) is SF's iconic 12-km costume race from Embarcadero to Ocean Beach with 50,000+ runners, many in elaborate costumes (or nothing at all). Hotels begin climbing toward summer peak.
Travel score
San Francisco May Weather Stats
Avg High
19°C
Avg Low
12°C
Rainy Days
3
18mm total
Sunshine
10h
Daily avg
Humidity
70%
Comfortable
UV Index
8
Very high
Wind
14 km/h
Gusts 32
Sea Temp
14°C
Avg water temp
Crowds
Busy
At attractions
May Sunrise & Sunset
Air Quality
PM2.5
9 μg/m³
PM10
18 μg/m³
Status
Good
Feels-Like Temperature & Wind
Feels like
Daytime
19°C
Nighttime
12°C
Humidity and wind affect how the actual temperature feels.
Wind
14 km/h
Max gust 32 km/h
Activities Recommended for May
May Travel Pros & Cons
Pros
- Weather 19/12°C ideal
- 90% sunny days
- Bay to Breakers spectacle
Cons
- Hotel rates climbing
May Events & Festivals
- Memorial Day (last Monday)
- Bay to Breakers (3rd Sunday in May)
San Francisco in May — Full Picture
May is peak spring — sunny, dry, mild. Bay to Breakers (3rd Sunday) is SF's iconic 12-km costume race from Embarcadero to Ocean Beach with 50,000+ runners, many in elaborate costumes (or nothing at all). Hotels begin climbing toward summer peak.
What to Wear & What to Pack
Late spring — high 19°C, low 12°C. Light layers, sunscreen. Fog beginning some mornings; clear afternoons.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
Current17.3°C
11°C
5.3/mo
Summer (Jun·Jul·Aug)
19.3°C
13.3°C
0.3/mo
Autumn (Sep·Oct·Nov)
20.3°C
12.7°C
3.7/mo
Winter (Dec·Jan·Feb)
14.3°C
8.3°C
10.3/mo
San Francisco Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 14° | 8° | 11d·110mm | 5h | 75% | 3 | Quiet | Low season | |
| 15° | 9° | 10d·110mm | 6h | 73% | 4 | Quiet | Low season | |
| 16° | 10° | 8d·75mm | 8h | 70% | 5 | Moderate | Shoulder | |
| 17° | 11° | 5d·35mm | 9h | 70% | 7 | Moderate | Shoulder | |
| May (Best) | 19° | 12° | 3d·18mm | 10h | 70% | 8 | Busy | Peak |
| 19° | 13° | 1d·5mm | 9h | 75% | 9 | Very busy | Peak | |
| 19° | 13° | 0d·0mm | 9h | 78% | 10 | Very busy | Peak | |
| 20° | 14° | 0d·0mm | 9h | 78% | 9 | Very busy | Peak | |
| 22° | 14° | 1d·8mm | 10h | 73% | 8 | Very busy | Peak | |
| 21° | 13° | 3d·28mm | 8h | 73% | 6 | Very busy | Peak | |
| 18° | 11° | 7d·70mm | 7h | 73% | 4 | Busy | Peak | |
| 14° | 8° | 10d·110mm | 5h | 75% | 3 | Very busy | Peak |
View Other Months
San Francisco May Hotel Picks
Frequently Asked Questions
Is May a good time to visit San Francisco?
San Francisco in May is Excellent. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in San Francisco in May?
San Francisco May averages a high of 19°C and a low of 12°C.
Does it rain much in San Francisco in May?
San Francisco May averages 18mm of rainfall over about 3 rainy days.
What should I wear in San Francisco in May?
Late spring — high 19°C, low 12°C. Light layers, sunscreen. Fog beginning some mornings; clear afternoons.
What time are sunrise and sunset in San Francisco in May?
San Francisco May sunrise is 06:00 and sunset is 20:15, with 14h 15m of daylight.
What's the air quality like in San Francisco in May?
San Francisco May air quality (AQI) averages 35, rated Good. PM2.5 averages 9μg/m³.
What activities are recommended in San Francisco in May?
In May, San Francisco is great for Golden Gate Bridge bike, Alcatraz, Bay to Breakers.
Is May peak season in San Francisco?
San Francisco May crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit San Francisco
View Other Months
Planning a May trip to San Francisco?
You've checked the weather — next come the budget and the route.
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.