A week of highs: See where climate change made heat worse in America

Last week, 96 percent of people in the contiguous United States experienced nighttime temperatures more likely to occur due to human-caused warming. The findings come from a Washington Post analysis of data provided by the nonprofit Climate Central, which released the world’s first tool to show how climate change is affecting daily temperatures in real time.

Overnight temperatures, as opposed to daytime temperatures, were boosted the most by climate change. While more and more people are increasingly exposed to warmer nighttime temperatures, which are potentially more dangerous to the body, last week’s number...