Environment & Science

What's behind Southern California's recent heat and humidity?

An image of the high pressure zone about to move over Southern California.
An image of the high pressure zone about to move over Southern California.

Listen to story

Download this story 1MB

If you think it's hot now, brace yourself - it's about to get worse.

Forecasters say Thursday and Friday could see temperatures hit 10 to 20 degrees above normal in some areas.

That's because a massive high pressure zone is about to move over the region, said Stuart Seto of the National Weather Service. Such systems, he explained, are usually associated with warmer weather.

As for the humidity, blame storms off the coast of Baja California.

"The storms form off the coast out there and when they fall apart they get pulled up into our area," Seto noted.

They're pulled up by the edge of that massive high pressure zone which has been moving that moist air up the coast, making things hot and sticky in Los Angeles.

On some days L.A. has seen relative humidity reach 60 percent in the afternoons, which can make 94 degrees feel like 110.

"Your body can't release the moisture because there is so much moisture around you," Seto explained. "So your body can't cool itself off."

This high humidity has helped lock in the heat overnight - leading to some record breaking temperatures. Burbank saw its highest ever recorded minimum temperature last week. 

There is some good news. As the high pressure front moves over California Thursday and Friday it should push out that humidity, said Stuart Seto.

In the meantime, stay hydrated and cool.