San Diego in May

In May, San Diego averages 20°C (68°F) during the day and 14°C (58°F) at night, with around 9 days of rain (16 mm total).

High season

Conditions are comfortable for sightseeing without being sweltering. Occasional showers are likely but won't dominate.

May is a great month to visit San Diego: pleasant temperatures and relatively few wet days.

20°C
Avg high
14°C
Avg low
9
Rain days
16 mm
Rainfall

How May compares to the rest of the year in San Diego

7th
warmest month of the 12
2nd
wettest month of the 12
5%
of yearly rainfall falls in May
13 h 50 min
daylight on the 15th

May is in the middle of the year for warmth in San Diego (7th of 12) and one of the wettest months (2nd of 12). Daytime temperature runs 1°C below the annual average (21°C). May runs roughly the same as April (20°C) and warms a further 2°C into June (22°C).

May sunrise & sunset in San Diego

🌅
Sunrise (15th)
5:49 AM
🌇
Sunset (15th)
7:40 PM
Day length
13 h 50 min

Times shown for San Diego local time (America/Los_Angeles), calculated for the 15th of May. They shift by a few minutes day to day across the month.

Photography light in San Diego — May

Golden-hour and blue-hour windows for the 15th of May, in San Diego's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
4:49 AM – 5:29 AM
🌄 Golden hour (AM)
5:29 AM – 6:29 AM
🌇 Golden hour (PM)
7:00 PM – 8:00 PM
🌆 Blue hour (PM)
8:00 PM – 8:40 PM
Milky Way galactic core
Good
Galactic core is up but lower on the horizon; head well outside city limits for a clean view.

📅 When to book — San Diego in May

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on May's tier (High season) and San Diego's popularity.

✈ Flights — lead time
2-3 months
Prices are above off-season but not the absolute peak. Tuesday/Wednesday departures are usually cheaper than weekend ones.
🏨 Lodging — lead time
2-3 months
Wide selection still available at this lead time. Premium properties book first; consider 'last-minute deal' availability at 2-week mark if your dates are flexible.

Crowds & pricing — May in San Diego

High season

This is a busy month in San Diego — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.

Why this tier: excellent tourism weather

Sun & mosquito risk — May in San Diego

☀️ UV Index (noon, 15th)
12.5
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●○○
Moderate
Active mosquito season. DEET 25-30% repellent recommended, especially at dawn/dusk.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Sea temperature in San Diego — May

17.9°C (64°F)
cool
swimmable but bracing — wetsuit helps for long sessions

Across the year San Diego's sea swings from 14.7°C (February) to 21.5°C (August) — May sits at 17.9°C.

San Diego in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 18°C / 64°F 9°C / 48°F 62 mm 8
February 18°C / 65°F 9°C / 48°F 48 mm 8
March 19°C / 65°F 11°C / 51°F 44 mm 11
April 20°C / 68°F 13°C / 55°F 22 mm 8
May 20°C / 68°F 14°C / 58°F 16 mm 9
June 22°C / 72°F 16°C / 61°F 2 mm 4
July 25°C / 76°F 18°C / 65°F 5 mm 2
August 26°C / 78°F 19°C / 66°F 9 mm 3
September 26°C / 78°F 18°C / 65°F 11 mm 5
October 24°C / 76°F 16°C / 60°F 10 mm 5
November 21°C / 70°F 12°C / 53°F 28 mm 6
December 18°C / 64°F 9°C / 48°F 63 mm 8

Other cities with similar May weather

🌍 See the full ranked list of climate twins for San Diego in May →

Frequently asked questions

How hot is San Diego in May?

In May, San Diego averages a high of 20°C (68°F) and a low of 14°C (58°F) — generally mild and pleasant.

Does it rain a lot in San Diego in May?

May sees occasional rain in San Diego, with about 9 rainy days on average.

Is May a good time to visit San Diego?

May is mild and pleasant. It suits travelers who are comfortable with mild and pleasant weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for San Diego in May?

Pack light layers for warm days and cooler evenings. See the full May packing list for San Diego for a complete, climate-based checklist.

Open San Diego on the interactive map

Check the live 10-day forecast and sunrise/sunset.