San Diego climate
San Diego (California, United States) has a hot semi-arid climate (Köppen BSh). The average temperature over the year is 19 °C67 °F, and about 269 mm11 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
San Diego climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 1967 | 1050 | 1559 | 411.6 |
| Feb | 2067 | 1050 | 1559 | 552.2 |
| Mar | 2170 | 1152 | 1661 | 291.1 |
| Apr | 2272 | 1254 | 1763 | 170.7 |
| May | 2576 | 1456 | 1966 | 80.3 |
| Jun | 2882 | 1560 | 2271 | 140.5 |
| Jul | 3188 | 1965 | 2577 | 40.2 |
| Aug | 3289 | 1967 | 2678 | 40.2 |
| Sep | 3187 | 1966 | 2577 | 60.2 |
| Oct | 2780 | 1661 | 2271 | 150.6 |
| Nov | 2373 | 1356 | 1864 | 251.0 |
| Dec | 1966 | 1050 | 1558 | 512.0 |
| Year | 3289 | 1050 | 1967 | 26911 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 64% | 50% | 3.2 | 10:13 |
| Feb | 66% | 56% | 4.1 | 10:58 |
| Mar | 68% | 60% | 5.2 | 11:53 |
| Apr | 68% | 60% | 6.1 | 12:57 |
| May | 68% | 72% | 6.1 | 13:50 |
| Jun | 63% | 81% | 5.9 | 14:18 |
| Jul | 58% | 75% | 6.1 | 14:06 |
| Aug | 57% | 69% | 6.1 | 13:21 |
| Sep | 57% | 59% | 5.4 | 12:19 |
| Oct | 60% | 54% | 4.3 | 11:18 |
| Nov | 60% | 50% | 3.4 | 10:26 |
| Dec | 64% | 51% | 2.9 | 10:00 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of San Diego is like
The warmest month is August, with an average high of 32 °C89 °F and a low of 19 °C67 °F. The coldest is December, when highs average 19 °C66 °F and lows 10 °C50 °F. There is a clear seasonal cycle, with 11 °C19.8 °F between the average temperature of the warmest and the coolest month.
It is dry, with about 269 mm11 in of precipitation per year. The wettest three-month stretch is December–February, which brings 55% of the annual total. Months with less than 20 mm0.8 in on average: April–October. The wettest month is February (55 mm2.2 in), the driest is August (4 mm0.2 in).
Relative humidity ranges from 57% in August to 68% in April. The clearest skies (lowest average cloud amount, 50%) are typical of January. Average wind speed near the ground ranges from 7 km/h (4 mph) in September to 9 km/h (6 mph) in April. Daylight lasts from about 10.0 hours in December to 14.3 hours in June.
Best time to visit San Diego
Based on these averages, the most comfortable months for sightseeing and outdoor activities are October–June: average highs of 19 °C66 °F to 28 °C82 °F with 8 mm0.3 in to 55 mm2.2 in of precipitation per month.
The most challenging month is August, which is hot, with average highs of 32 °C89 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for San Diego
- Winter (December–February) — highs 1966 to 20 °C67 °F, lows around 10 °C50 °F, about 49 mm1.9 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket.
- Spring (March–May) — highs 2170 to 25 °C76 °F, lows 1152 to 14 °C56 °F, about 18 mm0.7 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 2882 to 32 °C89 °F, lows 1560 to 19 °C67 °F, about 7 mm0.3 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water and an extra layer for the cooler mornings and evenings.
- Autumn (September–November) — highs 2373 to 31 °C87 °F, lows 1356 to 19 °C66 °F, about 15 mm0.6 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
How San Diego compares
Compared with Tijuana, about 28 km to the southeast, San Diego is on average 0.5 °C0.9 °F warmer and receives a similar amount of precipitation. The difference is largest in January (0.5 °C0.9 °F warmer).
Of the 222 places in the United States covered by World Climates, San Diego is the 44th warmest by annual mean temperature and the 211th wettest by annual precipitation. See all of them on the United States climate page.
Places in other countries with the most similar temperature and rainfall pattern (seasons shifted for the other hemisphere where needed): Tijuana (Mexico, BSh), Ensenada (Mexico, BSh) and Colina (Chile, BSh).
Nearby places
- El Cajon 21 km · 20 °C68 °F · 320 mm13 in
- Tijuana 28 km · 19 °C66 °F · 269 mm11 in
- Escondido 45 km · 20 °C67 °F · 320 mm13 in
- Oceanside 57 km · 18 °C64 °F · 314 mm12 in
- Temecula 87 km · 20 °C68 °F · 299 mm12 in
- Murrieta 93 km · 17 °C63 °F · 298 mm12 in
- Ensenada 108 km · 19 °C66 °F · 255 mm10 in
- Santa Ana 132 km · 17 °C63 °F · 311 mm12 in
Frequently asked questions
What is the warmest month in San Diego?
August is the warmest month in San Diego, with an average high of 32 °C (89 °F) and an average low of 19 °C (67 °F).
What is the coldest month in San Diego?
December is the coldest month, with an average high of 19 °C (66 °F) and an average low of 10 °C (50 °F).
When does it rain the most in San Diego?
February is the wettest month with about 55 mm (2.2 in) of precipitation; August is the driest with about 4 mm (0.2 in).
What is the best time to visit San Diego?
Judging by long-term averages, the most comfortable months are October–June.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 394 m, while San Diego lies at about 20 m. Temperatures on this page were therefore adjusted by +2.4 °C4.4 °F using the standard lapse rate of 6.5 °C per 1,000 m.