San Diego weather in January
Long-run climate averages for San Diego, CA in January, plus what the forecast models say for the days ahead.
In January, San Diego averages 62°F by day and 46°F at night. It is the wettest month of the year here.
January in San Diego averages a daytime high of 62°F and an overnight low of 46°F, which reads as mild for this part of the world. It is among the three coldest months of the year here. It is also the wettest month, so build rain into any plan. Across the whole year San Diego sees roughly 19 inches of precipitation.
Climate averages tell you what to pack. They do not tell you what next Tuesday looks like - for that, see the live San Diego forecast with every model compared and how much they currently agree.
San Diego weather by month
what to expect in San Diego through the yearHere is San Diego's typical weather in each month: the average daytime high and overnight low in °F, how each month feels, and the wettest month marked. Use it to plan any trip to San Diego by season.
Bottom line: over the last 30 days the American model has been the most accurate forecast for San Diego, scoring 87/100 on our CheckWeather Score, ahead of the European at 60. See the full US accuracy scoreboard for exactly how every model is tested.
Common questions
How warm is San Diego in January?
Is January a good time to visit San Diego?
Does it rain a lot in San Diego in January?
Climate averages from ERA5 reanalysis. Model accuracy re-scored over a rolling 30 days. Page updated .