the 10 US Cities Where the Most People Die from Extreme Heat

Heat is the leading weather-related cause of death in the United States. According to the Centers for Disease Control and Prevention, extreme heat is linked to an average of 1,220 fatalities every year in the United States. In 2023 alone, heat-related deaths hit a 21st century-high of 2,415, more than the death toll of any major climate disaster in the continental U.S. – including Hurricane Katrina – since at least 1980. 

Global temperatures have been steadily rising for decades, driving up incidents of heat-related fatalities. The global warming trend shows no signs of slowing and the toll extreme heat is taking on public health will likely only get worse – particularly in certain U.S. cities where dangerously high temperatures are already commonplace. 

In major population centers across parts of Arizona, California, Nevada, and Texas, summer temperatures regularly rise into the triple-digits. One hundred-plus degree-heat in these places poses existential risks, particularly to those who spend time outdoors or who lack access to air conditioning. 

Using data from the CDC, Climate Crisis 247 identified the cities where the most people die from exposure to excessive heat. We aggregated county-level data to the metro area level, and calculated the number of heat-related fatalities per 100,000 residents between 2018 and 2024. Only the 10 metro areas with the highest heat fatality rates are listed. Data on 30-year average summer temperatures and record-high temperatures by city are from the National Oceanic and Atmospheric Administration’s U.S. Climate Normals program and the Northeast Regional Climate Center. Supplemental data on  the share of households without air conditioning is from the Census’ Local Air Conditioning Estimates program.

10. Flagstaff, AZ

• Heat related deaths, 2018-2024: 1.1 per 100,000 people (11 total)
• Households in Flagstaff with no air conditioning: 22.8% (12,232 total)
• Avg. summer temperature in Flagstaff: 64.1°F (80.1°F daily high; 48.2°F daily low)
• Highest recorded temperature in Flagstaff: 99°F on July 28, 1898

9. Portland-Vancouver-Hillsboro, OR-WA

• Heat related deaths, 2018-2024: 1.3 per 100,000 people (108 total)
• Households in Portland with no air conditioning: 11.3% (113,511 total)
• Avg. summer temperature in Portland: 68.3°F (79.5°F daily high; 57.2°F daily low)
• Highest recorded temperature in Portland: 116°F on June 28, 2021

8. Laredo, TX

• Heat related deaths, 2018-2024: 1.5 per 100,000 people (28 total)
• Households in Laredo with no air conditioning: 0.6% (478 total)
• Avg. summer temperature in Laredo: 88.5°F (100.1°F daily high; 76.9°F daily low)
• Highest recorded temperature in Laredo: 115°F on June 19, 2023

7. Sierra Vista-Douglas, AZ

• Heat related deaths, 2018-2024: 1.5 per 100,000 people (13 total)
• Households in Douglas with no air conditioning: 2.5% (1,261 total)
• Avg. summer temperature in Douglas: 79.7°F (95.1°F daily high; 64.4°F daily low)
• Highest recorded temperature in Douglas: 111°F on June 19, 2016

6. El Centro, CA

• Heat related deaths, 2018-2024: 1.7 per 100,000 people (22 total)
• Households in El Centro with no air conditioning: 0.6% (293 total)
• Avg. summer temperature in El Centro: 90.4°F (106.0°F daily high; 74.8°F daily low)
• Highest recorded temperature in El Centro: 122°F on June 20, 2017

5. Tucson, AZ

• Heat related deaths, 2018-2024: 2.1 per 100,000 people (152 total)
• Households in Tucson with no air conditioning: 1.2% (5,169 total)
• Avg. summer temperature in Tucson: 87.1°F (100.0°F daily high; 74.2°F daily low)
• Highest recorded temperature in Tucson: 117°F on June 26, 1990

4. Phoenix-Mesa-Scottsdale, AZ

• Heat related deaths, 2018-2024: 2.5 per 100,000 people (893 total)
• Households in Phoenix with no air conditioning: 0.5% (9,429 total)
• Avg. summer temperature in Phoenix: 93.7°F (105.2°F daily high; 82.2°F daily low)
• Highest recorded temperature in Phoenix: 122°F on June 26, 1990

3. Las Vegas-Henderson-Paradise, NV

• Heat related deaths, 2018-2024: 3.2 per 100,000 people (512 total)
• Households in Las Vegas with no air conditioning: 0.8% (6,769 total)
• Avg. summer temperature in Las Vegas: 90.8°F (102.2°F daily high; 79.5°F daily low)
• Highest recorded temperature in Las Vegas: 120°F on July 7, 2024

2. Yuma, AZ

• Heat related deaths, 2018-2024: 6.1 per 100,000 people (91 total)
• Households in Yuma with no air conditioning: 1.4% (1,075 total)
• Avg. summer temperature in Yuma: 92.8°F (105.4°F daily high; 80.2°F daily low)
• Highest recorded temperature in Yuma: 124°F on July 28, 1995

1. Lake Havasu City-Kingman, AZ

• Heat related deaths, 2018-2024: 19.6 per 100,000 people (299 total)
• Households in Lake Havasu with no air conditioning: 1.8% (1,741 total)
• Avg. summer temperature in Lake Havasu: 93.8°F (107.5°F daily high; 80.2°F daily low)
• Highest recorded temperature in Lake Havasu: 121°F on June 27, 1990