Updated

After a winter marked by little snow and warmer temperatures, fire crews in Alaska are tackling two large wildfires burning on mostly treeless tundra in the southwest part of the state.

Weekend rain helped tamp down the lightning-caused fires that, through Monday, have burned 63 square miles in the Yukon Delta National Wildlife Refuge.

Fish and Wildlife Service fire ecologist Lisa Saperstein says Alaska gets fewer fires in tundra than in forests, but adds they are not unheard of.

She says tundra fires are more common in southwest Alaska, but rare above the Arctic Circle. The current fires are burning about 400 miles below the Arctic Circle.

According to a 2013 report by the University of Alaska Fairbanks Cooperative Extension Service, climate change could be a factor in a growing number of fires in tundra ecosystems over the next century.