San Diego Weather Averages

San Diego, California has an exceptionally moderate climate. Summers are cool and winters are warm. Storms are uncommon and rain is infrequent.

This page gives detailed information on annual temperature, precipitation, snow, sun, humidity, wind and storm averages for San Diego. The numbers here are historical averages based on climate data gathered at the San Diego International Airport, located on San Diego Bay near the city center.

Temperature Weather iconTemperature

71 °F annual average high 22 °C
59 °F annual average low 15 °C

San Diego's coldest days of the year usually occur in the second half of December when the daily maximum temperature averages 66 degrees Fahrenheit (19 degrees Celsius) and the minimum averages 49 °F (9 °C).

The year's hottest days are normally in late August. The average temperature peaks then with daily highs of 78 °F (26 °C) and nighttime lows of 68 °F (20 °C).

192 days 70 °F max. or more (21 °C)
60 days 50 °F min. or less (10 °C)

Normally every day in San Diego has a temperature of 50 °F (10 °C) or more. The city averages three days a year when the thermometer reaches into the 90s °F (over 32 °C). The temperature doesn't normally climb above 100 °F (38 °C), even on the hottest days.

At night, the thermometer dips to 40 °F (4 °C) or below on average just once a year. San Diego usually never cold gets cold enough for frost.

Rainy Weather iconPrecipitation

9.8 in total precipitation 249 mm
40 days of rain or snowfall

January and February are usually the wettest months of the year in San Diego, while summer months are the driest. San Diego's dry climate means that no month averages a total rainfall of more than 2.3 inches (58 mm).

Snowy Weather iconSnow

0 in total snowfall 0 cm
0 days with new snow

It normally never snows in San Diego. On rare occasions, the airport weather station has recorded a trace of snow.

Sunny Weather iconSun

68 % sunshine
146 days clear skies

The sun's rays reach the ground in San Diego during 68 percent of daylight hours on average year round, for a total of 3022 hours annually. Typically on 146 days a year the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in San Diego averages 12 hours and 10 minutes a day. The shortest days of the year in mid December have 10 hours and 0 minutes of daylight. The year's longest days in mid June last 14:19 from sunrise to sunset.

Humid Weather iconHumidity

69 % average humidity

The annual average for relative humidity in San Diego ranges throughout the day from 76 percent in the early morning to 58 percent at 1:00 pm.

Local Time1 am4 am7 am10 am1 pm4 pm7 pm10 pm
Humidity % 76 76 74 62 58 62 71 75

Windy Weather iconWind

7.0 mph wind speed average 11.3 kph

May is usually the windiest month for San Diego, and the wind is calmest during December.

Stormy Weather iconStorms

6 days precipitation of 0.5 inches (13 mm) or more
3 days with thunderstorms a year

Heavy rainstorms are infrequent and snowstorms unheard of in San Diego. The city averages just two days a year when it rains an inch (25 mm) or more.

Thunderstorms, although not common in San Diego, can arrive at any time of the year.


The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals.

San Diego Weather
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