Temperature for January
In San Diego, CA during January the average high temperature is 64.9°F. The hottest day on record was January 19, 2009 when the temperature hit 87.1°F.
Precipitation for January
In January the average monthly rainfall in San Diego, CA is 1.66 inches with rain usually falling on between 7 and 8 days. 1948 was the driest January with only 0.00 inches of rain falling, and 2005 was the wettest January with 6.40 inches of rain. The wettest single day in January was 8 January 2005 when 2.82 inches of rain fell.
In January it usually snows on between 0 and 1 days. In January there have been some years when thunderstorms have occurred, although there are other years when there hasn't been a thunderstorm in January.