Much of CA under red flag warning. How’s that different from fire weather watch?
Much of Northern California will be under a red flag warning over the weekend due to heightened wildfire risks caused by hot, dry conditions and gusty winds.
The National Weather Service in Sacramento originally issued a fire weather watch Thursday for communities across the Sacramento Valley, Delta and Sierra Nevada foothills, and upgraded it to a red flag warning on Friday.
Areas affected by the warning, in effect from Saturday morning through Sunday morning, include Sacramento, Yolo, San Joaquin and Stanislaus counties.
Meanwhile, a red flag warning was in effect in the northeastern part of the state through Friday, the weather service said.
In response to elevated fire risks, Pacific Gas and Electric could cut off electricity to customers in at least 15 California counties, including Stanislaus, San Joaquin, Merced and Fresno counties.
Public safety power shutoffs were expected to continue through Sunday, PG&E said.
What is a red flag warning? How does it differ from a fire weather watch?
Here’s what to know:
What is a fire weather watch? A red flag warning?
During wildfire season, the National Weather Service has two advisories that inform people of dangerous conditions that could lead to blazes: a fire weather watch and a red flag warning.
In both cases, the weather service said, “The combination of gusty winds and low humidity can cause fire to rapidly grow in size and intensity.”
Residents are told to “avoid outdoor activities that can cause a spark near dry vegetation, such as yard work, target shooting or campfires.”
The difference between the two is the amount of time before the weather conditions start, Anna Wanless, a meteorologist with the National Weather Service’s Sacramento office, previously told The Sacramento Bee.
A watch is issued up to 48 hours before the weather event starts, while a red flag warning is issued when critical fire conditions are expected within the next 24 hours.
What’s the difference between fire watch and warning?
The weather service will usually issue a red flag warning after a fire weather watch with a few exceptions, according to Wanless.
In addition, the weather service alerts suggest different measures people should take.
A watch warns people to be ready for potentially critical conditions, while a warning urges people to take action.
“Red flag warning is to take action now, and a watch is more be prepared,” Wanless said.
How bad will California wildfires be this summer?
With much of California expected to experience above-normal temperatures in June, July and August, experts are predicting that wildfire season could be worse than usual in 2025.
Wildfire season typically runs from May to November, with most fires happening during the summer months, according to the Western Fire Chiefs Association.
The National Interagency Fire Center predicts an “above-normal” risk for significant wildfires across much of California from June through August, according to its latest seasonal outlook.
“Outlooks for Northern and Southern California both paint a picture of a significant increase — (a) pretty widespread, elevated risk of large fires come August,” John Abatzoglou, a climatologist at UC Merced, previously told The Bee.
Is my California home at risk for wildfires? How to check
About 71.8 million homes in the United States had minor to extreme risk for wildfires in 2022, according to a study published by nonprofit research group First Street Foundation.
That number was expected to grow by 11.1% — to 79.8 million — by 2050 due to climate change.
More than 4.6 million properties in California, or about 40% of the state, had at least “moderate” risk of burning in a wildfire some time in the next 30 years, the study found.
You can see your California home’s risks for wildfires, floods and other threats by using Risk Factor, an online tool provided by First Street Foundation.
The tool also shows how many commercial and residential properties are at risk for fires, records of historic wildfires in your area and factors that make your area vulnerable for fires.
Go to the Risk Factor website and type your ZIP code into the search bar.
How can I prepare for fires?
During a fire weather watch, people who live in fire-prone areas should clear debris outside of their homes and create defensible space for safety, Wanless said.
During a red flag warning, people should avoid outdoor burning and using equipment that could create a spark.
Other fire safety tips include obeying local burn bans and not driving or parking vehicles in dry grass, which can be prone to catching fire.
This story was originally published June 20, 2025 at 11:07 AM with the headline "Much of CA under red flag warning. How’s that different from fire weather watch?."
