Hot Nights Fuel Wildfires in California, Complicating Containment

Over the July 4 weekend, hundreds of fires sparked across California, feeding on the hot, dry conditions of an ongoing heat wave.But some of these fires were strange.They grew rapidly and expanded their territory at a time when fires, like people, traditionally rest: at night.Overnight hours, when temperatures tend to go down and relative humidity, or the amount of water vapor in the air, goes up, can act as a…