Why California's Wildfires Have Burned So Much Area So Early This Season

California's wildfires have burned more than three times the acreage compared to this time last year.

The intense start is thanks to the thick grasslands left behind after this year's heavy rainfall.

While the rains may be the cause of bigger grass fires this year, they may help prevent the state's alpine forests from burning as badly.

California's wildfires have burned more than three times the acreage compared to this time last year.

UC Berkeley Fire Science Professor Scott Stephens says most of the fires so far have been in grassland areas that were revived from the rain, then dried out early during triple-digit heat waves.

"I think that really hot June weather dried out the fuels much more quickly and made them available to burn," Stephens says, "and now we're into just the beginning of August, late July and we're seeing these types of fires."

He says forests are better at retaining moisture and the Sierra will be more resilient this year because of the rains.

"I just think this will have some moderating impact. Certainly we'll have some fires in the Sierra Nevada. But fuel conditions in terms of fuel moisture are not going to be as low."

One concern, though, is the more than 100 million trees in the Sierra that have died recently due to the drought and bark beetle epidemic.