National Weather Service forecasters say near-record temperatures and wind gusts up to 50 miles per hour could lead to the explosive growth of wildfires across Montana in coming days.

Triple-digit temperatures were expected in eastern Montana, where crews are battling the 63-square-mile Delphia Fire. More than 400 personnel had the blaze east of Roundup 60 percent contained Tuesday.

Three other large fires in western Montana -- near the towns of Drummond, Condon and Ovando -- have scorched a combined four square miles. Crews are reporting some containment on each fire.

But new fires are possible as humidity levels drop into the single digits in parts of the state. By Wednesday, the heat will give way to a cold front preceded by gusting winds that could fan the flames.