Excessive Heat Warning, Flex Alert extended through Labor Day holiday weekend


The National Weather Service has extended an Excessive Heat Warning that was expected to last through Monday evening, pushing the warning period to include most of Tuesday and Wednesday as well.

The warning comes as several days of triple-digit weather is expected to impact much of interior Northern California, including all of Solano County.

The warning period now starts Sunday morning at 11 a.m. and lasts until Wednesday evening at 8 p.m. The original warning period was set to start Saturday morning and last until late Monday evening.

In a weather bulletin reviewed by Solano NewsNet, forecasters with the National Weather Service said high temperatures in excess of 100 degrees will create an extreme danger for both wildfires and heat-related illnesses, particularly on Labor Day and on Tuesday.

Record high temperatures are possible throughout Northern California, including in Solano County, where the temperature on Monday could reach 116 degrees in Vacaville, according to the Solano NewsNet weather portal.

Triple-digit temperatures are also expected in places like Vallejo and Benicia, which are typically cooler parts of the region. There, the high temperature on Monday could reach 103 degrees in Benicia and 102 degrees in Vallejo.

During periods of extreme heat, Solano Public Library locations are open as public cooling centers, offering locals access to things like air conditioning, bottled water and wireless Internet. Most local library branches were expected to be closed on Labor Day, but library officials say three branches — one each in Fairfield, Dixon and Rio Vista — will be open during special hours for those who need a place to cool off. The Benicia Public Library will also be open to the public on Monday.

Solano NewsNet is maintaining a list of cooling centers that will be available to the public during the holiday weekend. You can access that list by clicking or tapping here; the list is being updated as new cooling centers are announced.


The heat wave has prompted the state's energy regulator, California Independent System Operator (ISO), to issue Flex Alerts, a public notice encouraging residents and businesses to reduce their use of electricity in order to prevent strain on the power grid.

The Flex Alert asks for voluntary energy conservation between the hours of 4 p.m. and 9 p.m. During that time frame, residents and businesses are asked to curb their use of electricity-hungry appliances like air conditioners, dishwashers, electric stoves and clothes washers and dryers. Officials also encourage those with electric cars to charge them before the Flex Alert period, or hold off on charging them until after the Flex Alert is over.

On Friday, energy regulators issued their third consecutive Flex Alert in a row, adding that another Flex Alert would be issued on Saturday between 4 p.m. and 9 p.m. Officials are expected to continue issuing the alerts until at least Thursday, but more days could be added if the weather requires it.

Concerns over California's energy supply prompted a government liaison with the Pacific Gas & Electric Company (PG&E) to warn local officials earlier this week that rotating power outages might be possible if the electrical grid becomes strained.

According to sources familiar with the discussions, a PG&E government liaison said power brownouts were possible over the weekend if electrical demand surpasses the state's supply of power. The possibility of rotating brownouts in Solano County and Yolo County is low, the sources said, but that if electricity use does exceed the state's supply, PG&E may turn off power in some areas between the hours of 5 p.m. and 7 p.m., with each outage lasting about an hour.

Solano NewsNet first reported on that discussion Thursday afternoon. A PG&E spokesperson did not return a request for additional information until the utility began receiving inquiries from other media outlets about the possible brownout situation following our story.

Matt Nauman, a spokesperson for PG&E, eventually forwarded a message to Solano NewsNet that explained how California ISO issues Flex Alerts and revealed that the energy regulator declared an energy emergency earlier in the week. The message didn't offer any information about the liaison's discussions with local government officials in Solano or Yolo counties. 

I'm interested
I disagree with this
This is unverified