Downed trees and high winds took their toll on valley areas Monday.

Simi Valley was particularly hard it as Santa Ana winds knocked down trees and power lines, blocking roads in that city.

Red flag warnings were in force until Tuesday in the Santa Monica Mountains and Santa Clarita and San Fernando valleys, the foothills of the San Gabriel Valley and along the coast, in beach cities.

The threat of wildfire coincides with humidity levels of between 5 and 15 percent and what a National Weather Service statement called  “a moderate to strong Santa Ana wind event.”

In Simi, residents helped moved trees and debris out of roadways, assisting officers.

“Throughout the day, officers commented on how they were assisted by unofficial volunteer citizens who took the time to stop and assist them while they moved trees and debris out of the roadways so that vehicles would not be at risk or further delayed,” a Simi Valley Police Department statement said.