By 2100, according to climate models, the average summer day will be warmer than it is now. How much warmer, though, remains uncertain.
Climate Central, an independent organization of scientists and journalists, recently created an interactive map that estimates future temperatures for American cities. We've used this data, based on greenhouse gas emission scenarios developed by the Intergovernmental Panel on Climate Change, to look at what the future might hold for the West.
In the 11 cities shown here, you can see the current average summer high – Denver, 85.5 degrees Fahrenheit, for example – followed by two lines. The yellow line shows the projected temperature should emissions begin decreasing rapidly by 2020, thanks to, say, a drastic climate policy intervention. In that case, Denver's summer 2100 would feel like Coral Gables, Florida (88.1 degrees Fahrenheit) today, minus the humidity. But if emissions continue unabated, Denver's summers will follow the red line to Pharr, Texas (96.4 degrees Fahrenheit). Assuming current emissions continue, average summer highs are projected to increase 7 to 10 degrees Fahrenheit.