San Diego
California, USA
Long-term weather forecast
Long-term weather forecast

Monthly weather forecast and climate
San Diego, CA

The view of Coronado Island in San Diego, California, from across a water body on a sidewalk, with a row of palm trees
The view of Coronado Island in San Diego, California, from across a water body on a sidewalk, with a row of palm trees
San Diego has a semi-arid climate (Köppen climate classification BSh) that borders on the Mediterranean type (Köppen climate classification Csa) with hot and dry summers, and cold and wet winters. San Diego lies in the southern part of the American state of California on the Pacific Ocean coast near the Mexican border. The ocean governs the climate near the seaside, while the desert influences the eastern side beyond the mountains.

San Diego has different microclimates within short distances of each other due to the city's topography that consists of the Bay, hills, mountains, canyons, and desert areas. The temperatures vary to a remarkably low degree over the year, but they differ across the microclimates. Summer fog is dense due to the thick cloud cover over the coastal areas, but the inland areas are hot due to the weak influence of the ocean.

Summers are warm, dry, and foggy as the cold currents engulf the coast. The average temperatures are between 62°F (16.7°C) and 76°F (24.4°C) from June to September with a peak at 76°F (24.4°C) in August. Winters are cold and wet with the average temperatures between 48°F (8.9°C) to 65°F (18.3°C). Spring and autumn are mild, pleasant, and relatively dry. Annual precipitation is hardly above 10" (254mm), with the majority occurring between December and March. Snow is rare and falls on the mountain peaks, but the nights are occasionally frosty during the winter in San Diego.

San Diego has a pleasant climate for the majority of the year, with 3050 hours of sunshine. The average humidity lies in the range of 63% to 75%, but the rainfall is scanty due to the influence of the desert on the eastern side. San Diego is prone to earthquakes due to its location near major fault lines.

The highest temperature on record for San Diego is 111°F (43.9°C), set on September 26, 1963, while the record for the lowest temperature is 25°F (-3.9°C), set on January 7, 1913.
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The best time to visit San Diego is during the summer from June to September when the temperatures are in the 60°F (15.6°C) to 80°F (26.7°C) range. The days are pleasant, but the city is a popular tourist destination throughout the year. San Diego has mild summer temperatures compared to most of the cities in the United States. Spring and autumn are mild but tend to be damp compared to the summer. Summers have a singular fog around the coast, typically in June, that keeps the weather cool.

Although there is hardly any extreme weather period over the year, the worst time to visit San Diego is during the cold and wet winter. December to February sees the majority of the annual precipitation, and the winter brings storms with occasionally heavy rainfall. The days are the shortest in December, and a cold front may drop the night temperatures in the chilly zone. Though snow is mostly absent, the nights and mornings may be frosty.

San Diego is prone to earthquakes as it lies in the Pacific Ring of Fire in California. Two significant faults - the Hayward Fault and the San Andreas Fault are close to San Diego, which results in the occurrence of minor earthquakes regularly, and moderate to major occasionally. San Diego's infrastructure development mandates safe building codes as it faces a threat from major earthquakes.

January is the wettest month with 2.1" (53.3mm) of rainfall in San Diego as the mild winter continues its peaceful march. Weather in January »

February has mild temperatures during the winter of San Diego with the average lows and highs in the range of 51°F (10.6°C) to 65°F (18.3°C). Weather in February »

The average temperatures are in the agreeable 43°F (6.1°C) to 66°F (18.9°C) range as the skies host the sun for a daily 8.4 hours. Weather in March »

April has beautiful spring weather in San Diego with many sunny days. Temperatures rarely drop below 50°F (10°C), and a few days go past 70°F (21.1°C). Weather in April »

May has dry and cloudy weather in San Diego with the average temperatures in the 59°F (15°C) to 69°F (20.6°C) range. Weather in May »

June is the beginning of the San Diego summer, which brings pleasant temperatures in the 62°F (16.7°C) to 71°F (21.7°C) average range. Weather in June »

July is the sunniest as well as the most humid month in San Diego, with 305 hours of monthly sunshine amid average humidity at 75%. Weather in July »

August is usually the warmest month in San Diego with the highest average low and high temperatures of the year at 67°F (19.4°C) and 76°F (24.4°C) respectively. Weather in August »

September sees the average temperatures in the 65°F (18.3°C) to 76°F (24.4°C), and the warm days are an extension of the summer season. Weather in September »

October lies during the autumn season of San Diego, with mostly dry and sunny weather. The average temperatures are in the 63°F (17.2°C) to 71°F (21.7°C) range. Weather in October »

November lies during the fall season of San Diego with cool temperatures in the 54°F (12.2°C) to 69°F (20.6°C) average range. Weather in November »

The average temperature lies in the 48°F (8.9°C) to 65°F (18.3°C) range, with most days in December touching at least 60°F (15.6°C). Weather in December »

The month with the highest number of rainy days is February (7.1 days).
The month with the lowest number of rainy days is August (0.4 days).

The best month for swimming (with the highest average sea temperature) is August (67.9°F).
The coldest month (with the lowest average sea temperature) is February (58.7°F).