Many Americans are worried about extreme heat and understand it is affected by climate change. In Spring 2023, this research found that most Americans (72%) are at least “a little” worried about extreme heat harming their local area – and extreme heat tops the list of worries about climate impacts (e.g., droughts, flooding, water shortages). Additionally, a large majority of Americans (75%) think that global warming is affecting extreme heat at least “a little,” including 42% who say global warming is affecting it “a lot.” Over the past five years, Americans have grown more worried that extreme heat might harm their local area, increasing +9 percentage points from 35% in March 2018 (13% “very;” 21% “moderately”) to 44% in April 2023 (21% “very;” 24% “moderately”). The percentage of Americans who are “very” worried about extreme heat harming their local area has also increased over time (+8 points).