Much of Southern California will continue to wake up to May gray weather, but as the marine layer fades later this week, warmer temperatures and a spike in heat are expected to hit the inland areas.
The coastal areas will continue to see May gray in the morning and patchy fog that clears out in the afternoon, keeping temperatures fairly mild for the next two days.
Temperatures from the beaches to downtown Los Angeles will be in the high 60s to high 70s, which is normal for this time of year, according to the National Weather Service.
“The cool, moist ocean air that is pretty prevalent in May and June will still be around,” and persist through the week but will burn off in the middle of the day, said Ryan Pittell, a meteorologist with the National Weather Service in Oxnard. “It should shrink such that at least the warmest part of our valleys, including the Northridge and Chatsworth areas, may not experience much of it, which will allow them to warm up into the 90s as well.”
The effects of the cool, moist air will be felt along the coast, in downtown Los Angeles and in some areas of the San Gabriel Valley, Pittell said.
Moving toward the end of the week, Wednesday into Thursday, the marine layer will moderate as the temperature warms up, bringing above-average temperatures Thursday and Friday.
For the coast and downtown Los Angeles areas, meteorologists predict highs mainly in the 80s on Friday. Warming trends in the Inland Empire will peak as much as 10 to 15 degrees above the average for the area, with highs ranging from the 90s to 100 degrees; 103 to 109 degrees for the lower deserts.
Temperatures across Southern California are expected to dip on Saturday and into the following week.
Temperatures will climb so high that there is the possibility of a heat advisory or warning for the inland and desert areas on Friday, said Pittell. But even if a formal warning is not issued, he said residents should take precautions against the heat toward the end of the week.
“Anyone who has plans to do anything that’s pretty active outside during the day on Friday and Saturday, the best course of action is just to adjust those plans as much as you can and try to do [the planned activity] in the earlier part of the day,” he said.
And then plan to spend the rest of the day in a cool or air-conditioned room.
Adjusting the scheduled time of the outdoor activity to two hours earlier in the morning, Pittell said, “could be the difference between life and death.”
On May 10, a 38-year-old man died while participating in a half marathon on a Thousand Oaks trail on a day that the National Weather Service issued a heat advisory for the area, the Ventura County Star reported. The temperatures on that day were in the high 90s, and four other marathon participants had reportedly fallen ill.
“We’re coming out of our cool season and these types of temperatures in July and August are to be expected, but when they’re happening in May our bodies just haven’t had time to acclimate to it,” Pittell said.