Air Temperatures in San Diego

Trailhead at Iron Mountain in Poway

In the areas of Poway and La Mesa, it's a similar picture to Coastal Inland temperatures in the winter months. Temperatures hover between lows in the 50s and highs in the 70s, remaining comfortable without dipping too low to enjoy outdoor activities like hiking and sightseeing.

Temperatures can climb to the mid- to high-80s in the summer months, reaching their peak in August and remaining warm until October.

In the transition zone, the mercury can climb into the 90s with pleasant average high temperatures from November until May. Interestingly, Ramona experiences some of the lowest winter temperatures, dropping down as low as 37 degrees in December.

While it’s a good idea to bundle up if you’re planning on spending the day or evening outdoors on particularly cold days in winter, these low temperatures aren’t very common. You can expect that only on rare occasions will the temperature drop down below 50 degrees in most regions, even at night.

We love the Julian Beer Co for its food and beer!

With the increase in elevation, the mountain area in and around Julian has some of the widest range of temperature variance in all of San Diego. There’s plenty of heat, with highs for the year averaging 86 degrees in the summer months of July and August and average low temperatures dipping just below 40s in the winter months of December, January and February.

San Diego’s mountains are also one of the few places where snowfall occurs during the winter! While it’s very rare for most of Southern California to experience a white Christmas, precipitation isn’t nearly as uncommon at higher elevations.

To have the best chance at experiencing a snowy day in San Diego, visit during January or February, though occasional snow showers have been recorded in March.

Teddy Bear Cholla Cactus in Anza Borrego Desert State Park

In the desert around Borrego Springs, an average air temperature of well over 100 degrees is not uncommon in June, July, and August. However, you can still expect comfortable low temperatures in the 70’s overnight even during the warm summer months.

Variations between daytime highs in the bright direct sunshine and overnight lows can range 30 degrees or more. With low humidity and precipitation, the cool dry air in San Diego’s desert region can feel pleasant against the skin in the evenings, especially during the fall and spring seasons.