Extreme heat over Southern California will continue for one more day Monday before slowly easing throughout the rest of the week, prompting California officials to extend a Flex Alert.
The weather system pushing temperatures up will weaken in San Diego County starting Tuesday, according to forecasters.
"It expires later this weekend and for the rest of the week, it'll slowly start to cool down," NBC 7 Meteorologist Sheena Parveen said.
But first, the mountains and deserts will experience another day of high temperatures.
Get San Diego local news, weather forecasts, sports and lifestyle stories to your inbox. Sign up for NBC San Diego newsletters.
An excessive heat warning was in effect for the deserts until 8 p.m. Monday as temperatures soar into the 110 to 115-degree range. In the mountains, where temperatures are expected to be in the 90s, a heat advisory will remain in effect until 8 p.m. Monday.
Parveen said there’s a slight cooldown inland in the First Alert Forecast this week – back down to “close to seasonable” temps but it’ll still be warm. Along the coast, temperatures are comfortable and sunny.
The extreme heat -- combined with wildfires in Oregon that were making transmission lines unreliable -- prompted the California Independent System Operator (ISO) to ask Californians to conserve electricity Monday evening to avoid straining the electric grid.
The statewide alert will be in effect from 4 to 9 p.m.
Flex Alerts are issued when the electricity grid is overtaxed due to high temperatures, the ISO said. It is a voluntary call on residents to conserve electricity when demand is at its peak.
Before the Flex Alert takes effect, Californian's are encouraged to take the following steps to be comfortable and help grid operators balance electricity supply and demand:
- Pre-cool your home by lowering the thermostat
- If you need to use your major appliances, do it before the Flex Alert is in effect,
when solar energy is plentiful
- Close window coverings to keep your home or apartment cool
- Charge electronic devices and electric vehicles so there’s no need to do it later,
when solar generation is down
When the Flex Alert is in effect, consumers should conserve electricity by turning off unnecessary lights, not using major appliances and setting air conditioner thermostats to 78 degrees or higher, especially in the late afternoon and early evening when the grid is most stressed, the ISO said.
More energy-saving tips can be found on the FlexAlert website.
During extreme heat, San Diegans are urged to take extra precautions to avoid illness, like drinking plenty of water, staying indoors and in air-conditioned rooms whenever possible, and checking on relatives and neighbors. Those who are outside should wear light and loose clothing, taking frequent rest breaks and save strenuous activities for the early morning or evenings.