The Brief Nearly all U.S. states experienced above-average summer temperatures in 2025, with Utah showing the highest deviation from normal. New data reveals that extreme heat was evident in nearly all U.S. states this past summer. 1 in 5 people on planet felt climate change influenceBy the numbers:According to Climate Central, at least one in five people on the planet felt a strong climate change influence every day from June to August 2025. Exposure to extreme heat can cause serious but preventable heat-related illness and, in severe cases, fatal heat stroke. South Korea also felt the impacts of extreme heat, recording 21 tropical nights in July and reporting 19 heat-related deaths.