We're just about a month away from the official start to the summer monsoon.  

But, Southern California has already seen some monsoon storms develop over our mountains.  

What You Need To Know

  • Monsoon storms usually drench the Southwest between mid-June to the end of September

  • Storms benefit SoCal's mountain and desert cities but they could also lead to flooding rain
  • Storm chances, which began last week Wednesday, will begin to fizzle out early this week

  • A drier and sunny forecast is expected from Tuesday through this upcoming weekend

Summer is generally a dry season for Southern California except when summer monsoon storms fire up across the Southwest.

With the right set-up in the upper levels of the atmosphere, some of those storms could pop up over SoCal mountains, and even drift over the foothills and valleys at times.   

Storm clouds on Friday building over Lake Baldwin, east of Big Bear Lake (Spectrum News)

We here in SoCal may not like the extra humidity when monsoonal moisture travels our way from the south and southeast.  

But the storms that this moisture-rich air can bring over the region can be a welcome sight during a drought. 

Although, you might say we're doing well in the rain department thanks to all the winter and spring storms we had.   

Why monsoon storms can be dangerous

Slow-moving thunderstorms could dump drenching rainfall, which can trigger flash floods and mud and debris flows.  This is especially dangerous over burn scars.

Last summer, monsoon storms brought all of the above across SoCal. 

Yermo flash flooding on July 19, 2022 (Caltrans District 8)
Mud and debris flow along Hwy 38 (Caltrans District 8)

This kind of rainfall is not enough to fill the reservoirs.  

We need the kind of major soaking that only winter storms can bring.

Yes, this past winter brought record rainfall. 

But, experts say we’ll need more than just one robust winter season to get us completely out of this drought.  

If the forecast holds, the rest of this week will remain free of monsoon storms.  

Our team of meteorologists dives deep into the science of weather and breaks down timely weather data and information. To view more weather and climate stories, check out our weather blogs section.