The county is under a Red Flag Warning until Tuesday afternoon.
Fire officials say hillsides that were green just a couple of weeks ago are now brown and dry.
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"The experts are saying the fuels in the area are where they normally are in July. They are dried out to the point that we could potentially see fires today like we would ordinarily see in July," said Vacaville Fire Chief Kris Concepcion.
He does not like what he sees in this weather forecast.
"Humidity in single digits into tomorrow. That is very serious. Anytime you have high temperatures and low humidity and gusty winds- we are supposed to have gusts up to 40mph- we need to take it seriously," he said in an interview Monday morning.
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Firefighters experienced what that weather can do on Sunday when a fire broke out near Hay and Dally Roads in rural Solano County. It spread quickly with help from the winds, even jumping Hay Road. There were no reports of property damage but fire officials say this should put people on notice that they need to be ready.
"I urge residents to start preparing and make sure they are ready. If they need to be evacuated be ready to evacuate. Know what you are going to take, important papers and medications. The most important thing is to make sure your property is ready, that there are no combustible materials around the house."
He says fire crews will be patrolling the streets during the Red Flag Warning, looking for any issues.