San Diego weather

Our guide to the weather in San Diego during December

18

Average high

4

UV Index

59mm

Monthly rainfall

60%

Humidity

We've looked at the most up-to-date weather data for San Diego, covering the last 12 years up to 2026, plus we've asked our team of travel bloggers for their first-hand experiences in order to answer the most frequently asked questions about San Diego weather in December.

What's the temperature like in San Diego during December?

December is typically the coolest month in San Diego. The temperature reaches around 18℃ during the daytime, falling away to 12℃ at night. The UV index will be moderate at this time of year, so not something to worry about for the average person. However, if you're going to be outside for long periods it's worth wearing a broad spectrum SPF 30+ sunscreen and UV-blocking sunglasses. Remember that bright surfaces, such as water and sand increase UV exposure.

Does it rain in San Diego during December?

December is typically the wettest month in San Diego. On average, there will be 2 rainy days during the month, amounting to 59.1mm in total. That's broadly comparable with the amount of rain we see in England during the summer months, and would be considered dry. You're not likely to see a thunderstorm during your trip.

Is it windy in San Diego during December?

You're unlikely to experience any strong winds. Expect a light breeze that picks up slightly at times in December. With moderate humidity and mild air temperatures, the breeze will have a slight cooling effect.

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San Diego Blog posts

From the UK's most popular travel bloggers

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11 best things to do in Joshua Tree National Park

17th March 2021 by Hand Luggage Only

California has a heap of gorgeous national parks to visit. From the gorgeous spots in Yosemite to the desert landscapes of Death Valley, California has such a diverse mix of national parks to visit. And guess what, Joshua Tree is no exception! There are so many stunning and best things to do in Joshua Tree National Park that you really can’t miss. Around a 3-hour drive from the city of San Diego, it’s technically possible to visit Joshua Tree for a day but I’d definitely recommend longer....

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11 very best things to do in San Diego

24th March 2021 by Hand Luggage Only

Nestled right on the West Coast, San Diego is one epic place to visit in California. With gorgeous beaches, historic districts and enough foodie spots to fill any tummy, it’s the kind of city that’s perfect for a long weekend trip. In fact, there’s so many epic and best things to do in San Diego that I’d suggest an even longer one....

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Experiencing the best of SoCal in San Diego

27th June 2019 by PommieTravels

If California were a family, San Francisco would be the ultra-busy tech professional. Los Angeles would unquestionably be the diva of the outfit. And San Diego? They would be the laid back surfer bro who has a healthy addiction to fish tacos. In short, if you want a chilled-out California holiday, San Diego is where it’s at. It has incredible weather, it’s smaller than its two siblings, and its people are in no hurry to get anywhere. You’ll probably need a whip, though. Like other...

Weather in San Diego

Our month-by-month guide to the weather and climate in San Diego

19.1

San Diego weather in

January
18.3

San Diego weather in

February
18.6

San Diego weather in

March
19.6

San Diego weather in

April
20.3

San Diego weather in

May
22.6

San Diego weather in

June
24.8

San Diego weather in

July
26.0

San Diego weather in

August
26.2

San Diego weather in

September
24.1

San Diego weather in

October
21.6

San Diego weather in

November
18.2

San Diego weather in

December