Much of San Diego County should cool off again this week — albeit slowly — after a weekend of sudden, sometimes hazardous heat.
The heat “wasn’t anything extreme,” said Brandt Maxwell, a meteorologist with the National Weather Service.
But it made for a dramatic shift after a relatively cool spring, bringing not only much higher daytime highs but also unusually high overnight lows.
Those relatively warm nighttime temperatures contributed to its dangers, the NWS said.
In Otay Mesa, a brush fire charred more than 100 acres on Saturday. And in Rancho Peñasquitos, a hiker died in what appeared to be a heat-related death Sunday.
San Diego saw its first 80-degree day of the year, Maxwell said.
The temperature Saturday in Campo rose higher than it ever had before on that date, hitting 105.
And nightfall brought comparatively little relief. Overnight lows into Sunday were warmer than they had ever been in Vista, Escondido and Ramona.
Blame the humidity.
“That moisture aloft kind of acted as a blanket to keep most places unusually warm,” said Maxwell. “In a way, we kind of had an East Coast the past couple of nights.”
That made it tougher for buildings to cool off overnight. And the absence of the marine layer made for much quicker warming in the mornings.
But this week, a general cooling pattern will prevail — west of the mountains, anyway, forecasters say. Escondido could hit 84 on Tuesday (compared with a forecast high of 89 Monday), El Cajon 85 (versus 89) and San Diego 76 (nee 78).
It could also be a little less humid starting Tuesday night, Maxwell said, although the humidity may remain due to warmer local ocean temperatures.
The deserts are expected to remain hot, but the drop in overnight lows will lower the heat risk there.
And the mountains could get showers and thunderstorms into Tuesday, as cumulus clouds seen gathering above them Monday seemed to warn.
Here’s how hot it got Sunday around the county, according to the NWS:
Alpine: 94Borrego Springs: 110Brown Field: 88Carlsbad Airport: 81Chula Vista: 83
El Cajon: 94Encinitas: 84Fallbrook: 94Julian: 87La Mesa: 92
Lake Cuyamaca: 85Lemon Grove: 86Miramar MCAS: 91Mount Laguna: 86National City: 82
Oceanside Airport: 87Poway: 97Ramona Airport: 97Rancho Bernardo: 90San Diego Int’l Airport: 84
San Marcos: 90San Pasqual Valley: 98Santee: 98Valley Center: 97Vista: 91
