The 10 US Cities That Are Warming the Fastest Most are in California, Nevada, and Arizona By Arden Dier, Newser Staff Posted Jul 20, 2016 11:29 AM CDT 21 comments Comments A man sips water on a hot day in Phoenix. (AP Photo/Ross D. Franklin) (Newser) – The southwest corner of the US has long been known as a sweltering spot, but it's only getting hotter, according to Climate Central, which ranked 178 US cities based on temperature changes since 1965. All but three have seen temperatures rise in the past 50 years, but some are warming faster than others. Here are the top 10 fastest warming cities, based on the average temperature rise per decade: Reno, Nev.: 1.39 degrees Phoenix, Ariz.: 1.12 Las Vegas, Nev.: 1.04 Riverside, Calif.: 0.95 Prescott, Ariz.: 0.89 Chattanooga, Tenn.: 0.82 Tucson, Ariz.: 0.8 Minneapolis, Minn.: 0.76 El Paso, Texas: 0.75 Duluth, Minn.; Fargo, ND; St. Louis, Mo.: 0.72 Click for the full list, or check out the hottest US cities.