Although wildfires are a natural part of most Northwest forest ecosystems, warmer and drier conditions have helped increase the number and extent of wildfires in western U.S. forests since the 1970s. Warmer winters have led to reductions in the mountain snowpack that historically blanketed the region’s mountains, increasing wildfire risk. The warming trend is projected to be accentuated in certain mountain areas in late winter and spring, further exacerbating snowpack loss and increasing the risk for wildfires. In central Idaho and eastern Oregon and Washington, vast mountain areas have already been transformed by wildfires, but the western Cascades and coastal mountain ranges have less experience with this growing threats. Under the A1B emissions scenario, the median annual area burned in the Northwest would quadruple relative to the 1916 to 2007 period to 2 million acres (range of 0.2 to 9.8 million acres) by the 2080s. Averaged over the region, this would increase the probability that 2.2 million acres would burn in a year from 5% to nearly 50%. The limitation for these sorts of projections is that they do not account for changes in land use, fire suppression rates, or vegetation changes.