Warm weather descended on San Diego County today, with inland highs expected to teeter on the brink of the triple-digit mark.
By Thursday, inland temperatures could break 100 degrees, and desert highs could approach record levels, said Stan Wasowski of the National Weather Service.
"We've had a relatively mild August, so it will seem warmer," Wasowski said.
The heat, which will be accompanied by low humidity levels, is being caused by a warm air mass moving from southern New Mexico toward Southern California, where it is expected by Friday.
Because the warming trend is not being caused by an offshore flow, coastal temperatures will remain comfortable, possibly in the mid-80s, Wasowski said. However, highs in the valleys and mountain areas today will be between 89 and 99 degrees, according to the Weather Service.
The NWS forecast calls for triple-digit temperatures in El Cajon, Escondido and Ramona on Thursday and Friday. In Borrego Springs, the temperature could reach 115 to 116 degrees.
The heat wave is expected to plateau on Saturday, followed by a slight cooling trend, according to Wasowski, who said there's no monsoonal moisture on the horizon.
County health officials encouraged the public to take precautions to stay safe and healthy as temperatures rise into the triple digits.
"Avoid exercising during the hottest times of the day, between 10 a.m. and 4 p.m., and keep an eye on seniors and young children in your family and neighborhood," said Dr. Wilma Wooten, the county's public health officer. "These age groups are most at risk of suffering heat exhaustion and heat stroke."
Signs of heat stroke include, a body temperature higher than 103 degrees, lack of sweating, rapid pulse, headache, nausea, confusion and even unconsciousness.
Anyone with symptoms of heat stroke should be moved into the shade, cooled with water and a call placed to 911.
County health officials also reminded the public to keep an eye on their pets and never leave animals or children unattended inside a vehicle, where temperatures can quickly reach deadly levels.
