San Diego could see record-breaking heat on the first official day of summer, and the tail end of a five-day heat wave baking the County.
The day before San Diego's first day of summer, Ocotillo Wells, a desert city in the County, hit an all-time high of 124 degrees, breaking the all-time San Diego County high of 122, set in 2016.
“To put it into perspective, the highest temperature ever recorded anywhere on earth is Death Valley, at 134,” said NBC 7 Meteorologist Jodi Kodesh. “So, we were only 10 degrees shy of the hottest temperature ever recorded on earth.”
The National Weather Service (NWS) San Diego said a heat advisory remains in effect for San Diego’s inland valleys and foothills – including Santee, El Cajon, and Escondido – through 9 p.m. Wednesday. In those areas, temperatures are expected to hit between 95 and 103 degrees.
“You have to take extra precaution to stay cool and really evaluate, throughout the day that you are taking care of yourself – drinking lots of water; frequent breaks in the shade if you have to be outside,” said NBC 7 meteorologist Jodi Kodesh.
Many residents in the inland areas of the county spent their time indoors. But some, like Spring Valley resident Deanna Vasquez, had no choice but to spend some time under the scorching sun for a graduation ceremony.
"It was outside and it was hot," Vasquez said. "We all had the programs in front of our faces to block the heat."
"It was fun walking and stuff but then when we sat down--it started to get hot," said Spring Valley Academy Graduate Kailey Sherry. "Make-up running down faces and everything."
Even some business had some difficulties.
"We've actually had machines saying I'm not going to work for a while and shut down for a couple hours," said Yogurt Mill manager Betty Brown. "Because of the heat."
The NWS said an excessive heat warning is also in effect in San Diego’s deserts, including Borrego Springs and Banning, through 9 p.m. Sunday. Temperatures are forecasted to hit 112 to 119 on Thursday.
Along the coast, however, temperatures will be significantly cooler, offering some respite from the heat wave.
“There will be a drastic difference between the coast, and the rest of the county,” said Kodesh. “Beaches will have morning clouds, that may linger, so highs will only be 67-78 degrees. Inland areas will range from 95 to 100, with deserts soaring to 118.”
Because of the hot weather, Three Sisters Falls will be closed Wednesday. The Cleveland National Forest will also be closed Wednesday.
San Diegans can expect the tail end of this five-day heat wave to make its way out by Thursday.
By then, inland temperatures will decrease a bit – to around 87 degrees. Same goes for Friday before a slight increase in temperatures for the weekend.
Heat-related illness is common under these conditions. Strenuous outdoor activities should be avoided or rescheduled to early morning or evening hours. People should drink plenty of water and wear light and loose-fitting clothing. Kids and pets should never be left unattended in hot cars, as car interiors can reach lethal temperatures within minutes amid heat waves like this.
With more residents expected to use their air conditioning systems at home to beat the heat, the California Independent System Operation Corporation (ISO), the state's power grid operator, has issued a statewide Flex Alert asking residents to voluntarily conserve electricity amid the heat wave. The Flex Alert is in effect between 2 p.m. and 9 p.m. Tuesday and Wednesday.