Thunder, lightning and rain headed to Northern California. When to expect showers
Most of Northern California is bracing for thunderstorms, heavy rain and strong winds as the remnants of Tropical Storm Mario push into the region.
Leftover moisture from the tropical storm will sweep into California and Southwestern deserts, the National Weather Service said in an X post on Tuesday, Sept. 16.
“That will bring “clouds and (a) chance of moisture to all areas,” the weather agency said in a Tuesday news release.
According to the National Weather Service, thunderstorms could bring rain to Northern California and parts of the Central Valley — including Sacramento, Modesto, Merced and Fresno.
How close is Tropical Storm Mario to California’s coast?
As of Tuesday afternoon, the storm was about 700 miles away from the Los Angeles coast, according to National Weather Service meteorologist Ryan Kittell.
While the system will weaken as it moves into California, Kittell said, it will still bring higher chances of rain and elevated humidity — creating sticky, muggy conditions across the state.
“Plan for extra time during commutes,” he told The Tribune. “Be aware of slick roadways, and if there are any thunderstorms, definitely stay aware and seek shelter if you hear thunder, see lightning or the winds are really increasing.”
Where will it rain in Northern California?
In areas across California, the National Weather Service said, there will be “light showers or even a thunderstorm.”
Thunder, lightning and rain were forecast for Fresno, Merced, Modesto and Sacramento.
Areas of San Luis Obispo County could also see rainfall, The Tribune previously reported.
When will storm reach Northern California?
According to the National Weather Service, moisture from the remnants of Tropical Storm Mario will push northward.
“Chances for showers and isolated thunderstorms are expected from Thursday into the weekend,” the weather agency said on X.
Are thunderstorms common this time of year?
Courtney Carpenter, a meteorologist with the National Weather Service, previously told The Sacramento Bee that thunderstorms aren’t “super frequent” this time of year.
“We can get them when monsoon moisture comes up north from the desert,” Carpenter told The Bee in August 2024.
What should I do if I’m caught in a thunderstorm?
When you are caught in a thunderstorm and can’t reach a safe location nearby, follow these tips from the National Weather Service:
- Avoid beach picnic shelters
- Avoid the tops of hills and open fields
- Avoid water
- Avoid trees and other tall objects
“Remember: if you see a flash, dash inside,” the weather agency said on X.
When is the start of fall in 2025?
The official start of fall is right around the corner.
In 2025, the autumn equinox lands on Monday, Sept. 22.
The autumn equinox signals the start of the fall season in the Northern Hemisphere, according to the Old Farmer’s Almanac. That’s when leaves start to change color, temperatures get cooler and days get shorter.
What is the fall weather forecast for California in 2025?
The Old Farmer’s Almanac said Californians should expect “steamy” trips to the pumpkin patch this fall.
The National Weather Service’s Climate Prediction Center called for warmer-than-usual weather across most of California in October, November and December.
The chance of above-normal temperatures ranges from 33% to 50%, according to the latest three-month outlook.
“’Normal’ is based on the average of all temperatures from 1991 to 2020, the weather agency previously told The Sacramento Bee.
In Northern California, the Old Farmer’s Almanac is predicting a warm September, with some scattered thunderstorms.
Will California see more rain this season?
According to the Old Farmer’s Almanac, October could bring about 2.5 inches of rain.
That is about 2 inches less than the typical rainfall for the month.
Meanwhile, the National Weather Service’s three-month outlook for September through November shows “equal chances” of the season being wetter, drier or around average.
This story was originally published September 17, 2025 at 12:39 PM with the headline "Thunder, lightning and rain headed to Northern California. When to expect showers."
