Average weather, temperature, rainfall, sunshine hours
Climate chart - San Diego
The climate of San Diego is
arid sub-tropical, with very mild, relatively rainy winters and warm, sunny summers. The city is located on the coast of California, in the far south-west of the United States, on the border with Mexico. Despite the low latitude (32 degrees north latitude), the climate is so mild, spring-like most of the year, because a cold current flows on the Pacific coast.
However, the temperature can increase a lot when the
Santa Ana blows, the wind from the deserts of inland areas.
At the Lindbergh Field International Airport, located on the coast, the cold record from 1981 to 2020 is 0.5 °C (33 °F), set in December 1988, while the heat record is 41.5 °C (107 °F), set in September of the same year.
Here are the
average temperatures.
San Diego - Average temperatures| Month | Min (°C) | Max (°C) | Mean (°C) | Min (°F) | Max (°F) | Mean (°F) |
|---|
| January | 9 | 18 | 13.9 | 49 | 65 | 57 |
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| February | 10 | 18 | 14.4 | 51 | 65 | 57.8 |
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| March | 12 | 19 | 15.2 | 53 | 66 | 59.4 |
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| April | 13 | 20 | 16.5 | 56 | 67 | 61.7 |
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| May | 15 | 20 | 17.8 | 59 | 69 | 64 |
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| June | 17 | 22 | 19.2 | 62 | 71 | 66.5 |
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| July | 19 | 24 | 21.2 | 65 | 75 | 70.1 |
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| August | 19 | 25 | 22 | 67 | 76 | 71.6 |
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| September | 18 | 24 | 21.4 | 65 | 76 | 70.5 |
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| October | 16 | 23 | 19.3 | 61 | 73 | 66.7 |
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| November | 12 | 21 | 16.3 | 54 | 69 | 61.3 |
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| December | 9 | 18 | 13.6 | 48 | 65 | 56.6 |
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| Year | 14.2 | 21 | 17.55 | 57.6 | 69.7 | 63.5 |
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in San Diego is scarce, given that it amounts to just 260 millimeters (10 inches) per year, so it is at a semi-desert level. However, the rainfall pattern is similar to that of the Mediterranean climate, but with a drier autumn, since most of the rain falls from December to March, while in summer it hardly ever rains. The wettest month is February. Here is the average rainfall.
San Diego - Average precipitation| Month | Millimeters | Inches | Days |
|---|
| January | 50 | 2 | 7 |
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| February | 60 | 2.4 | 7 |
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| March | 45 | 1.8 | 7 |
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| April | 20 | 0.8 | 4 |
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| May | 3 | 0.1 | 1 |
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| June | 2 | 0.1 | 1 |
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| July | 1 | 0 | 1 |
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| August | 0 | 0 | 0 |
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| September | 4 | 0.2 | 1 |
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| October | 14 | 0.6 | 3 |
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| November | 25 | 1 | 4 |
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| December | 40 | 1.6 | 6 |
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| Year | 265 | 10.4 | 42 |
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The amount of
sunshine in San Diego is good all year round, but especially in winter, when the sun shines 75% of the time. The least sunny months are May and June, due to the morning fog that forms on the coast and in the neighborhoods up to about 15 km (9 miles) away from the coast (the phenomenon is called
June gloom, even though it actually occurs in May and June, and sometimes in July). In total, there are 3,000 hours of sunshine per year. Here are the average sunshine hours per day.
San Diego - Sunshine hours| Month | Average | Total |
|---|
January | 7.5 | 240 | February | 8 | 225 | March | 8.5 | 260 | April | 9 | 275 | May | 8 | 250 | June | 8 | 240 | July | 10 | 305 | August | 9.5 | 295 | September | 8.5 | 255 | October | 8 | 245 | November | 7.5 | 230 | December | 7.5 | 230 | Year | 8.4 | 3055 |
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Due to the aforementioned cold current, the
sea in San Diego remains a bit cold even in summer: from July to October, the water temperature is of 19.5/20.5 °C (67/69 °F). Here is the average sea temperature.
San Diego - Sea temperature| Month | Celsius (°C) | Fahrenheit (°F) |
|---|
January | 15 | 59 | February | 15 | 59 | March | 15.5 | 60 | April | 16 | 60 | May | 17 | 62 | June | 18 | 64 | July | 19.5 | 67 | August | 20.5 | 69 | September | 20.5 | 69 | October | 19.5 | 67 | November | 17.5 | 64 | December | 16 | 61 | Year | 17.5 | 63.5 |
In the
inland areas, in the towns of San Diego county that in fact are part of the conurbation of the same city, the climate becomes more continental: winter nights are colder (sometimes the night minimum drops around freezing or even slightly below), while the days are warmer all year round.
Moreover, very hot days, with highs of 35 °C (95 °F) and more, are decidedly more frequent. In September 2010, 45 °C (113 °F) were reached (while at the international airport, the temperature didn't exceed 35 °C or 95 °F).
Here are the average temperatures at the Gillespie Field airport, near the town of El Cajon, about 28 km (17 mi) from the coast.
El Cajon - Average temperatures| Month | Min (°C) | Max (°C) | Mean (°C) | Min (°F) | Max (°F) | Mean (°F) |
|---|
| January | 6 | 21 | 13.5 | 43 | 70 | 56.3 |
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| February | 7 | 21 | 14 | 45 | 70 | 57.2 |
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| March | 9 | 22 | 15.5 | 48 | 72 | 59.9 |
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| April | 11 | 23 | 17 | 52 | 73 | 62.6 |
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| May | 14 | 24 | 19 | 57 | 75 | 66.2 |
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| June | 16 | 27 | 21.5 | 61 | 81 | 70.7 |
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| July | 18 | 30 | 24 | 64 | 86 | 75.2 |
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| August | 18 | 31 | 24.5 | 64 | 88 | 76.1 |
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| September | 17 | 30 | 23.5 | 63 | 86 | 74.3 |
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| October | 13 | 27 | 20 | 55 | 81 | 68 |
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| November | 9 | 24 | 16.5 | 48 | 75 | 61.7 |
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| December | 6 | 21 | 13.5 | 43 | 70 | 56.3 |
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| Year | 12 | 25.1 | 18.55 | 53.6 | 77.2 | 65.5 |
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When to go
Having a great climate, San Diego can be visited all year round. However, from December to March, it can rain, and it can get a bit cold at night, especially in inland areas. In May and June, there may be morning mists. In summer, but especially in September and October, there can be very hot days, when the wind blows from the desert.
The best time to go to the beach is from July to October, when the sea is less cold.
Back to
California.