If it feels hot to you now in the dog days of this summer, imagine a time when summertime Boston starts feeling like Miami and even Montana sizzles. Thanks to climate change, that day is coming by the end of the century, making it harder to avoid simmering temperatures.
Summers in most of the U.S. are already warmer than they were in the 1970s. And climate models tell us that summers are going to keep getting hotter as greenhouse gas emissions continue. What will this warming feel like? Our new analysis of future summers illustrates just how dramatic warming is going to be by the end of this century if current emissions trends continue unabated.
For our Blistering Future Summers interactive we have projected summer high temperatures for the end of this century for 1,001 cities, and then showed which city in the U.S. — or elsewhere in the world, if we couldn’t find one here — is experiencing those temperatures today. We’ve highlighted several striking examples on the interactive, but make sure to explore and find how much hotter summers will likely be in your city.
By the end of the century, assuming the current emissions trends, Boston’s average summer high temperatures will be more than 10°F hotter than they are now, making it feel as balmy as North Miami Beach is today. Summers in Helena, Mont., will warm by nearly 12°F, making it feel like Riverside, Calif.
In fact, by the end of this century, summers in most of the 1,001 cities we analyzed will feel like summers now in Texas and Florida (in temperatures only, not humidity). And in Texas, most cities are going to feel like the hottest cities now in the Lone Star State, or will feel more like Phoenix and Gilbert in Arizona, among the hottest summer cities in the U.S. today.
In some cases, summers will warm so dramatically that their best comparison is to cities in the Middle East. Take Las Vegas, for example. Summer highs there are projected to average a scorching 111°F, which is what summer temperatures are like today in Riyadh, Saudi Arabia. And at 114°F°, living in Phoenix will feel like summering in sweltering Kuwait City.
On average, summer heat is projected to warm 7-10°F, though some cities will have summers 12°F warmer than they are now. As you explore the interactive, you’ll find that for cities in the Northwest, the Great Plains, the Midwest, and the Northeast, warming is best illustrated by a southward shift. In some cases, however, the shift is slightly northward and inland — for example, warming in coastal San Diego will make it feel like Lexington, Ky., — and represents more than a 6°F temperature increase.
This analysis only accounts for daytime summer heat — the hottest temperatures of the day, on average between June-August — and doesn’t incorporate humidity or dewpoint, both of which contribute to how uncomfortable summer heat can feel. This projected warming also assumes greenhouse gas emissions keep increasing through 2080, just as they have been for the past several decades.