New atmospheric research has found melting sea ice in the Arctic increases the risks for wildfires on the West Coast.

Last week, a “thousand-year” heat wave baked the Pacific Northwest and adjacent British Columbia with widespread highs topping 100 degrees, resulting in a death toll in the hundreds. The Canadian province’s Lytton climbed to 121 degrees and established new national records three days in a row before the town burned in heat-intensified wildfires. The National Oceanic and Atmospheric Administration announced Friday that the heat wave helped the United States clinch its hottest June on record. Eight states had their hottest Junes, including Arizona, California, Nevada and Utah.

From floods to wildfires, mapping programs in Cascadia are showing scientists which communities face higher risk.