SAN DIEGO — An Excessive Heat Warning is now in effect as rising temperatures throughout the next week are expected to bring sweltering conditions to certain areas of San Diego County.

The warning was issued by the National Weather Service for Tuesday, July 11 through 8 p.m. on Sunday, July 16, as an expected prolonged heat wave during this timeframe is forecasted to bring dangerously high temperatures to the county’s desert and mountain areas.

These areas include the communities of Campo, Mount Laguna, Julian and Borrego Springs.

A strengthening high pressure system sitting aloft will slowly warm temperatures by several degrees per day over the next week, reaching its peak around the weekend.

Highs will run about three to eight degrees above normal by Thursday, according to NWS. The heat will continue to rise through Sunday, bringing temperatures anticipated by the weather agency to be the hottest of the year thus far.

NWS said highs could eclipse 120 degrees in certain areas of the desert, with other communities under the heat warning seeing temperatures ranging from 90 to 110 degrees.

A breakdown of the forecasted highs for the weekend can be found below:

  • Inland San Diego Valleys: 90-100 degrees
  • Mountains below 5,000 ft.: 99-108 degrees
  • High desert: 109-117 degrees
  • Lower deserts: 115-123 degrees

The placement of the high pressure could exacerbate some of the heat risk associated with these temperatures, NWS says, given that it may allow for some low and mid-level moisture to filter into Southern California, thus increasing humidity.

“Now is the time to prepare for this heat,” NWS said in a forecast discussion on Tuesday. “Drink plenty of water and stay hydrated, avoid any strenuous outdoor activities and work especially during the peak heating of the day, wear lightweight and loose-fitting clothing and check in on pets and loved ones, especially those more prone to heat-related illness.”

Local health officials urge that people are cognizant of the signs of heatstroke or exhaustion, including having a body temperature of 103 degrees or higher, dizziness, nausea, confusion and headache. If you’re suffering these symptoms, call 9-1-1 try to get cooled off immediately.

(National Weather Service)
(National Weather Service)

“Cool Zones” have also been deployed throughout the county for those looking to escape the extreme heat. More information about the free, air-conditioned sanctuaries can be found on the County Health & Human Services website.

Several San Diego-area hiking trails in the Cleveland National Forest have also been closed due to heat risk, including the River Gorge, Cedar Creek Falls, Three Sisters Falls and Eagle Peak trails. For those that plan on taking to any open trails, be sure to take precaution and hike safely.

While inland communities will feel the heat this week, NWS says that coastal communities will largely be spared from the excessive temperatures due to the presence of a shallow, but persistent, marine layer. Highs along the coast are expected to remain in the 70s to mid-80s through much of the heat event.

By early next week, the heat could wane slightly as the high pressure weakens and shifts east, according to NWS. However, the degree of cooling has not been determined by weather officials, given some atmospheric anomalies that will keep highs above normal for the foreseeable future.