San Diego weather in December

December is one of the least pleasant months in San Diego: highs of 17°C (62°F) and about 51 mm (2.0 in) of rain on average. Nights average 8°C (46°F) and cloud cover 51% (NASA POWER, 2001–2025 averages). The sea averages 16°C (61°F). It is the 2nd wettest month of the year and the coolest. Compared with November, it is cooler and wetter; January brings highs of 17°C (63°F) and 41 mm (1.6 in) of rain.

Is December a good time to visit San Diego?

least pleasant month Weather score 71/100.

December is one of the least pleasant months for weather in San Diego. For better conditions, consider Apr–May, Jul–Nov.

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Does it rain a lot in San Diego in December?

No, it is usually dry: about 51 mm (2.0 in) falls in an average December. It is the 2nd wettest month of the year.

How warm is San Diego in December?

Days average 17°C (62°F) and nights 8°C (46°F).

San Diego weather by month

Month	High	Low	Rain	Cloud	Sea	Weather
January	17°C (63°F)	8°C (46°F)	41 mm	50%	15°C (58°F)	least pleasant
February	17°C (63°F)	8°C (46°F)	55 mm	56%	15°C (60°F)	least pleasant
March	19°C (66°F)	9°C (48°F)	29 mm	60%	16°C (61°F)	fair
April	20°C (68°F)	10°C (49°F)	17 mm	60%	17°C (62°F)	best
May	22°C (72°F)	11°C (52°F)	7 mm	72%	18°C (65°F)	best
June	25°C (78°F)	13°C (55°F)	14 mm	81%	20°C (68°F)	fair
July	29°C (84°F)	16°C (61°F)	4 mm	75%	21°C (71°F)	best
August	29°C (85°F)	17°C (62°F)	4 mm	69%	22°C (71°F)	best
September	28°C (83°F)	17°C (62°F)	6 mm	59%	21°C (70°F)	best
October	25°C (76°F)	14°C (57°F)	15 mm	54%	19°C (65°F)	best
November	21°C (69°F)	11°C (51°F)	25 mm	50%	17°C (63°F)	best
December	17°C (62°F)	8°C (46°F)	51 mm	51%	16°C (61°F)	least pleasant

Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine. Page updated Oct 31, 2026. How we rate months

Nearby places in December

Los Angeles in December San Jose in December San Francisco in December