Residents had little warning when wildfires that ignited late Sunday night, October 8, 2017, were fanned by wind gusts of 50 miles per hour and blasted across California’s wine country. More than 100,000 acres have burned as of October 11, with less than 6 percent of the fires contained.

Many homes and businesses have been destroyed in the series of blazes, and many more remained threatened at the time Landsat 8 acquired the October 11 image. Evacuation orders continue.

A drought lasting more than 5 years left the region parched. Last winter’s abundant rainfall was welcomed, but it stimulated vegetation growth, which then dried out after a hot, dry summer and became fuel for these fires. Early fall is typically hot and dry in this part of northern California, and winds blowing over the mountain ranges are quickly spreading the wildfires.

Gray patches are populated areas in the valleys, though some are obscured by smoke in the October 11 image. Bright green is vegetation, and burned areas are maroon.

Landsat’s 30-meter resolution allows detailed mapping of burn severity. Its shortwave infrared (SWIR) and near-infrared (NIR) imaging provide an accurate distinction between burned and unburned vegetation.