Extreme Heat Days
The majority of Southerners experienced 15+ extreme heat days in 2021.
Number of extreme heat days (100°F Heat Index) by county
May - September 2021
Source: CDC/NASA. Notes: Data not available for Hawaii or Alaska.
2023 was the hottest year on record. The hottest 10 years, since NOAA began keeping records in 1850, have all been in the past decade. And temperatures will continue to climb. Scientists predict that 2024 has a 33% likelihood of being hotter than 2023.1
Heat has caused nearly twice as many deaths as flooding in the U.S. over the last 30 years.2 Humidity reduces the human body’s ability to self-cool, making days that are hot and humid particularly deadly.[3] Older adults, young children, people who are overweight, those with preexisting conditions like diabetes or heart conditions, and pregnant women are at great risk to experience damage to vital organs and even die from extreme heat (Pregnancy-related Deaths).[4]
According to the most recent data available by county, in 2021, 92% of Southerners (versus 61% of non-Southerners) were exposed to 5+ days of extreme heat. 64% of Southerners (versus 28% of non-Southerners) were exposed to 15+ days of extreme heat.
Air conditioning (AC) is critical for keeping vulnerable people safe during extreme heat days. And weatherization is essential for reducing energy costs. Lower-income households are less likely to have AC, even in the South where AC is more widely available. They also tend to live in older buildings with poor insulation. The Inflation Reduction Act includes substantial funding that can be used for home weatherization, but only via tax credits for homeowners.[5] Ensuring renters have homes that protect them from extreme heat and high utility bills will be an important focus for increasing community resilience (Unaffordable Housing).
2023 was the world’s warmest year on record, by far. (2024, January 12). National Oceanic and Atmospheric Administration; U.S. Department of Commerce. https://www.noaa.gov/news/2023-was-worlds-warmest-year-on-record-by-far
Weather Related Fatality and Injury Statistics. (n.d.). NOAA; U.S. Department of Commerce. https://www.weather.gov/hazstat/
Bohn, K. (2022, March 1). Humans can’t endure temperatures and humidities as high as previously thought | Penn State University. https://www.psu.edu/news/research/story/humans-cant-endure-temperatures-and-humidities-high-previously-thought/
Picture of America: Heat-Related Illness Fact Sheet. (n.d.). CDC. https://www.cdc.gov/pictureofamerica/pdfs/picture_of_america_heat-related_illness.pdf
Rabe, B. G. (2022, October 10). The U.S. needs better, more accessible home weatherization programs. Brookings. https://www.brookings.edu/blog/the-avenue/2022/10/10/the-u-s-needs-better-more-accessible-home-weatherization-programs/
