Annual snowfall has declined by nearly two feet since 1950. Because of steady warming, precipitation that once fell as snow now increasingly comes as rain. Annual precipitation could increase by 9 to 15 percent by the end of the century, the assessment says. But with snowpack decreasing and temperatures and evaporation increasing, future conditions are expected to be drier, stressing vegetation and increasing the risk of wildfires. Extreme weather is already more common, and blazes like Yellowstone’s massive 1988 fires—which burned 800,000 acres—are a growing seasonal worry. The assessment’s future projections are even bleaker. If heat-trapping emissions are not reduced, towns and cities in the Greater Yellowstone Area—including Bozeman, Montana and Jackson, Pinedale, and Cody, Wyoming—could experience 40 to 60 more days per year when temperatures exceed 90 degrees F. And under current greenhouse gas emissions scenarios, temperatures in the Greater Yellowstone Area could increase by 5 to 10 degrees F by 2100, causing upheaval in the ecosystem, including shifts in forest composition.