"When you look at what we've had over the last month or so, we've had a lot of these high temperatures, particularly in the Inland Empire, and we have seen an increase in fire starts," said Cal-Fire spokesman Bill Peters.
Cal-Fire says the fire agency is fully staffed and ready to respond should a fire start.
Weather conditions are projected to be light to no wind. That's good news for firefighters and homeowners.
A fire threatened Nancy and Art Bellante's Riverside home two weeks ago after a fire erupted in the Santa Ana river bottom. This weekend, the Bellantes are taking some precautionary measures.
"We water everything down and we just pray the wind shifts the other way," said Nancy Bellante.
The excessive heat is expected to bring triple-digit temperatures beginning on Sunday.
Cal-Fire reminds anyone who sees suspicious activity in drier brush areas to alert authorities by calling 911.