Cities are almost always hotter than the surrounding rural area but global warming takes that heat and makes it worse. In the future, this combination of urbanization and climate change could raise urban temperatures to levels that threaten human health, strain energy resources, and compromise economic productivity.
Summers in the U.S. have been warming since 1970. But on average across the country cities are even hotter, and have been getting hotter faster than adjacent rural areas. (report continues below interactive)