Climate Overview
The climate in San Diego is hot. The average annual temperature is 25°C and approximately 4016mm of precipitation falls per year. San Diego receives a notable amount of rainfall throughout the year, including during its driest month. San Diego is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, September. The coldest months are January, February, December, when temperatures can drop to 21°C.
Temperature
San Diego has relatively stable temperatures year-round, staying within a 10°C range. The warmest month is July, when average highs reach 31°C and the mean temperature sits around 26°C. January is the coolest month, with minimum temperatures around 21°C and an average of 25°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows.
Precipitation
San Diego is a very wet location, receiving approximately 4016mm of precipitation annually, which averages out to around 335mm per month. The wettest month is October, averaging 624mm of rainfall. May and September also tend to see above-average precipitation. The driest month is January, with just 43mm. That's 582mm less than October, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
San Diego is relatively calm, with an average annual wind speed of 8km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 10km/h, though still comfortable for most outdoor activities. The calmest conditions occur in May, with average winds dropping to 6km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 4km/h gap between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 9km/h in winter, 8km/h in spring, 7km/h in summer, 7km/h in autumn.
Seasons
88 days until Summer
It is currently spring in San Diego, which began on March 20, 2026. San Diego is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 31°C, while the coldest stretch bottoms out in January near 21°C. Summer is next, beginning on June 21, 2026 — 88 days from now.
Spring
Temperatures range from 21 to 30°C. Rainfall is heavy, totalling around 1217mm across the season with a monthly average of 406mm. Winds are generally light, averaging 8km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 23 to 31°C. Rainfall is heavy, totalling around 1144mm across the season with a monthly average of 381mm. Winds are generally light, averaging 7km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 22 to 30°C. Rainfall is heavy, totalling around 1470mm across the season with a monthly average of 490mm. Winds are generally light, averaging 7km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 21 to 30°C. Precipitation is moderate at around 185mm for the season, averaging 62mm per month. Winds are generally light, averaging 9km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Best Time to Visit
The best time to visit San Diego is during January and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 25°C with modest rainfall averaging 57mm per month. By contrast, July can be uncomfortably hot with temperatures reaching 31°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.
Monthly Climate Data
The table below shows monthly climate averages for San Diego based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
