Summers in the U.S. have been warming since the 1970s due to climate change, though it might not seem like it if you’re riding out this unusually cool August in the northeast and midwest.

If you're in a city, though, your perception of the heat might be all messed up. Cities get it the worst because of something additional known as the urban heat island effect. Due to all of the dark, paved surfaces in cities that are good at absorbing sunlight, urban areas tend to be hotter than their surrounding rural areas, where vegetation reflects more sunlight. That’s why green roofs have such environmental benefits; they help cool cities down.

Image: http://www.fastcoexist.com