Historical weather data, all-time temperature records, and monthly climate averages for El Cajon, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in El Cajon runs warm for early spring, with an average high of 75° and a low of 48°. That said, the date has surprised before — temperatures have swung from a scorching 98° in 1989 all the way down to 37° overnight in 2023. Rain is unlikely but not impossible, with just a 14% historical chance of any precipitation.
El Cajon earns its reputation as one of San Diego County's hottest inland spots — the all-time record of 114° set on September 5, 2020 is no joke. On the other end, Christmas Day 1987 brought a rare freeze at 25°, and a single December storm in 2010 dumped 3.8 inches of rain in one day. It's a place of real extremes tucked just 15 miles from the coast.
El Cajon stays mild year-round, with monthly average highs ranging from a comfortable 69° in late December to a sizzling 91° during the first week of September. If you're heat-sensitive, stick to winter and early spring — though even January and February average a pleasant 70°. The wettest stretch runs late February into early March, but 'wet' is relative: expect just under three-quarters of an inch on average that week.