Triple-digit temperatures were expected Sunday in Sonoma County following a sizzling 24 hours when the mercury hit 100 degrees at the Sonoma County Charles M. Schulz Airport and even higher in other parts of the region.

The National Weather Service issued a heat advisory for the North Coast’s interior valleys to warn people to make preparations for the heat to continue.

Fire warnings were also in place because the same high pressure ridge producing the heat was fueling winds, creating weather patterns with the potential to spark wildfires.

The “red flag warning” was issued for areas above 1,000 feet in Sonoma County starting at 5 p.m. Saturday and lasting until 9 p.m. Sunday.

After that, the heat should dissipate, with high temperatures forecast in the 90s Monday and into the 80s the rest of the week, National Weather Service meteorologist Steve Anderson said.

You can reach Staff Writer Julie Johnson at 707-521-5220 or julie.johnson@pressdemocrat.com. On Twitter @jjpressdem.