San Diego in August

In August, San Diego averages 26°C (78°F) during the day and 19°C (66°F) at night, with only about 3 rainy days.

Peak season

Conditions are comfortable for sightseeing without being sweltering. Skies are generally dry and clear.

It's peak hurricane season in San Diego during August. Travel is possible but expect storm risk, possible flight disruption, and generally lower travel insurance coverage.

26°C
Avg high
19°C
Avg low
3
Rain days
9 mm
Rainfall

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

2nd
warmest month of the 12
11th
wettest month of the 12
3%
of yearly rainfall falls in August
13 h 22 min
daylight on the 15th

August is one of the warmest months in San Diego (2nd of 12) and one of the driest months (11th of 12). Daytime temperature runs 4°C above the annual average (21°C). August runs 1°C warmer than July (25°C) and stays flat into September.

August sunrise & sunset in San Diego

🌅
Sunrise (15th)
6:12 AM
🌇
Sunset (15th)
7:34 PM
Day length
13 h 22 min

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

Photography light in San Diego — August

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

🌅 Blue hour (AM)
5:12 AM – 5:52 AM
🌄 Golden hour (AM)
5:52 AM – 6:52 AM
🌇 Golden hour (PM)
6:54 PM – 7:54 PM
🌆 Blue hour (PM)
7:54 PM – 8:34 PM
Milky Way galactic core
Fair
Core only briefly above the horizon — a marginal month even from dark sites near San Diego.

📅 When to book — San Diego in August

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 August's tier (Peak season) and San Diego's popularity.

✈ Flights — lead time
3-5 months
Flight prices are near their annual peak. Watch fare-alert tools, book directly when you see a fare under the typical range for this city. ⚠ Peak hazard season — book flexible-change tickets and travel insurance with weather-disruption coverage.
🏨 Lodging — lead time
3-5 months
Reasonable selection still available at 3-4 months out, but central locations vanish first.

Crowds & pricing — August in San Diego

Peak season

San Diego is in peak season during this month — expect bigger crowds at famous sights, higher hotel and flight prices, and longer queues. Restaurant reservations a few days out are advisable, and any boutique hotels you have your eye on should be booked weeks ahead. The trade-off: most attractions, restaurants, and seasonal services are fully open, the weather is at its most reliable, and the city feels at its most alive.

Why this tier: excellent tourism weather Northern Hemisphere summer holidays beach-season conditions peak hazard season (1 active)

Sun & mosquito risk — August in San Diego

☀️ UV Index (noon, 15th)
12.1
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 — August

21.5°C (71°F)
pleasant
warm enough for most swimmers without a wetsuit

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

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

Frequently asked questions

How hot is San Diego in August?

In August, San Diego averages a high of 26°C (78°F) and a low of 19°C (66°F) — generally warm.

Does it rain a lot in San Diego in August?

August is generally dry in San Diego, with about 3 rainy days on average.

Is August a good time to visit San Diego?

August is warm and mostly dry. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for San Diego in August?

Pack light layers for warm days and cooler evenings. See the full August 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.