The heat wave that has kept Southern California sweating since Monday went into a third day Wednesday, setting some temperature records while again raising fears of heat-related illnesses.
In a bit of relief for some residents, the National Weather Service canceled an excessive heat warning in an area stretching from the coast to downtown Los Angeles, replacing it with a less severe heat advisory that will remain in effect until 8 p.m. Thursday.
According to the NWS, daytime highs in that area were expected to range from 72 to 82 degrees at the beach and up to 92 degrees inland. Forecasters noted that the heat advisory still means residents should expect hot temperatures and high humidity that can lead to illness.
But the news wasn’t all good. In fact, the excessive heat warning in the rest of Los Angeles County that had been scheduled to expire at 8 p.m. Thursday was instead extended to 8 p.m. Friday. High temperatures in the affected areas were expected to range from 98 to 108 degrees, except in the Antelope Valley, when highs are anticipated from 107 to 112 degrees, according to the NWS.
NWS forecasters said Tuesday and Wednesday would be the hottest days of this week’s heat wave. Woodland Hills reached 109 degrees Wednesday afternoon, breaking the 107-degree record for a July 25 set in 1959. Palmdale tied the 1975 record of 109.
It was the second day in a row a heat record was set in Woodland Hills. That area reached 108 degrees on Tuesday, breaking the record of 107 set on July 24, 2006. Lancaster reached 109 degrees on Tuesday, tying the record also set in 2006.
Overnight low temperatures have offered little reprieve from the heat, ranging from 66-76 degrees.
Conditions will create “increased potential for serious heat-related illnesses, especially for the young and elderly, those performing outdoor activities, as well as those without access to air conditioning,” the NWS warned in a statement.
The heat wave will also create an increased potential for power outages because of the widespread use of air-conditioning, prompting the California Independent System Operator — which manages the state’s power grid — to issue a statewide Flex Alert that calls for voluntary electricity conservation from 5-9 p.m.
Southern California residents were urged to take steps to protect themselves from the conditions, scheduling strenuous activities for the coolest part of the day — in the morning or evening — wearing lightweight and light-colored clothing and drinking plenty of water.
NWS forecasters also stressed that “young children and pets should never be left unattended in vehicles under any circumstances. This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.” The warning also covers seniors.
Health officials also warned against leaving children or the elderly alone at home without air conditioning.
“Extreme heat such as this is not just an inconvenience, it can be dangerous and even deadly,” said Dr. Jeffrey Gunzenhauser, Los Angeles County’s interim health officer. Even a few hours of exertion can cause severe hydration, heat cramps, heat exhaustion and heat stroke, he said.
Frail individuals or those with chronic health problems are particularly at risk and Gunzenhauser urged residents to make sure that elderly or infirm neighbors without air conditioning get to a cooling center or other air-conditioned space during the day. A map of cooling centers can be found at www.lacounty.gov/heat or residents may call 211.
“While it is very important that everyone take special care of themselves, it is equally important that we reach out to those who are especially vulnerable to the harmful effects of extreme heat, including children, the elderly and their pets,” Gunzenhauser said.
A catastrophe in France in 2003 gave weight to Gunzenhauser’s warnings. Close to 15,000 heat-related deaths occurred that year, mostly in August, mostly affecting seniors whose families were vacationing.
Pets should not be left out in the sun or in garages, which are typically uninsulated and can reach extremely high temperatures.
Along the coast, a high surf advisory will be in effect until 9 p.m. in L.A. and Orange counties. Surf of 4-8 feet with maximum sets of 8 feet are expected in L.A. County whit Orange County is expected to get surf of 5-7 feet with 8-foot sets.
Forecasters said swimming conditions will be dangerous, in part because of rip currents.