SD Swelter: See Top Temperatures Recorded Across The County

SAN DIEGO, CA — Extreme and record temperatures were set in a few areas of San Diego County this week as a brutal heat wave continued to bear down on the Golden State.

The heat wave began Monday, then intensified Tuesday and Wednesday.

"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors," the National Weather Service advised. "Young children and pets should never be left unattended in vehicles under any circumstances."

Campo reported a record high of 105 for Aug. 31, tying the mark set in 1998. On Friday, the high in Campo was 100 degrees.

Some of the highest temperatures on Friday were felt in Borrego Springs, 111 degrees; Ocotillo Wells, 111 degrees; Fallbrook, 101 degrees; Ramona, 99 degrees; Escondido, 97 degrees and Oceanside, 87 degrees.

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On Saturday some of the highest temperatures in San Diego County were forecast in Ramona, 104 degrees; Escondido, 104 degrees; Borrego Springs, 111 degrees and Ocotillo Wells, 111 degrees.

Here are the top 10 hottest temperatures recorded across the Southland on Friday.

1. Riverside - 104 degrees - 11:55 a.m.
2. Fallbrook - 103 degrees - 11:55 a.m.
3. Rimln2 - 101 degrees - 11:14 a.m.
4. San Bernardino - 101 degrees - 11:55 a.m.
5. Chino - 100 degrees - 11:55 a.m.
6. Murrieta Hot Springs - 99 degrees - 11:55 a.m.
7. Hesperia 99 degrees - 11:55 a.m.
8. Ramona - 99 degrees - 1155 a.m
9. Ramona - 99 degrees - 11:55 a.m.
10. San Diego - 98 degrees - 11:55 a.m.

An excessive-heat warning is in effect for parts of San Diego County until 8 p.m. Tuesday. Dangerously hot conditions with temperatures between 85 to 96 degrees are in the forecast for San Diego coastal areas. Extreme heat is expected in Oceanside, Vista, Carlsbad, Encinitas, Chula Vista, National City and San Diego.

San Diego valleys and mountains will experience extreme heat as well. Temperatures in the valleys are expected to be between 97 and 105 degrees and in the mountains between 91 and 101 degrees.

The excessive-heat warning also is in effect in Escondido, El Cajon, San Marcos, La Mesa, Santee, Poway, Julian and Pine Valley.

Forecasters urged residents to be aware of the signs of heat stroke.

"Take extra precautions if you work or spend time outside," the NWS cautioned. "When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose-fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location."

Amid a statewide call for residents to cut back on their electricity use during the heat wave, Glendale Water and Power officials warned Friday the utility may be forced to implement rolling blackouts early next week if customers don't conserve.

The utility issued the warning Friday morning in hopes of encouraging more of its customers to slash their electricity use.

"Without major conservation efforts during this week's heat wave, GWP may be forced to implement rolling power outages to its customers starting 9/4 (to) 9/6 for approximately one hour at a time," the utility announced on its Twitter page.

The California Independent System Operator, which manages the state's power grid, has issued Flex Alerts for three consecutive days, calling on residents to voluntarily reduce their power use between 4 and 9 p.m. Friday will be the third straight day of the alerts, and Cal-ISO has warned that more are likely over the weekend.

Residents are asked to make the following adjustments under the alert:

• Set thermostats to 78 degrees or higher
• Avoid using large appliances
• Avoid charging electric vehicles
• Turn off unnecessary lights

"Lowering electricity use during that time will ease strain on the system, and prevent more drastic measures, including rotating power outages," grid operators wrote in a statement.

So far, residents have heeded the call, and the state's electrical grid has operated without any major interruptions during the beginning stages of the heat wave. If the Flex Alerts fail to result in reduced power usage and the system is strained, Cal-ISO could ultimately impose rolling power cuts.

Despite the state's recent push for residents to ditch gas-powered cars, the utility grid operator has asked residents to avoid charging their electric vehicles. The request to avoid charging such vehicles comes days after the state announced plans to ban the sale of gas-powered cars by 2035.

If weather or grid conditions worsen, grid operators said they may issue a series of emergency notifications to access additional resources.

"We will be seeing dangerously warm temperatures this weekend," the National Weather Service tweeted out of its Bay Area office.

In what’s forecast to be the most extensive heat wave in California this year, temperatures in Northern California are expected to be 10-20 degrees warmer than normal through next week. In Southern California, temperatures are expected to climb 10-18 degrees warmer than usual.

"An extended period of dangerous heat will impact much of our area over the holiday weekend and into early next week. All populations will be at risk for heat-related illnesses. Drink plenty of water, seek air conditioning, and avoid outdoor activities during the day," NWS officials said.