Most people vulnerable to extreme heat, US counties
US counties ranked by the estimated number of people with three or more heat-related social-vulnerability risk factors in 2022, from the Census Bureau's experimental Community Resilience Estimates for Heat (experimental, modeled data). Los Angeles County, California leads at 2,956,807. 3,144 counties qualify in total. California carries 8 of the top 25 entries.
UPDATED 2026-07-15 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES
Frequently asked
Which county has the highest residents vulnerable to extreme heat?
Los Angeles County, California ranks #1 with 2,956,807 (2022 American Community Survey).
What are the top 5 counties by residents vulnerable to extreme heat?
Los Angeles County, California, Cook County, Illinois, Harris County, Texas, Maricopa County, Arizona, Kings County, New York.
How many counties are in this ranking?
3,144 counties qualify after filtering for population minimums and data availability. The ranking covers 2022 ACS 5-year data.
How is residents vulnerable to extreme heat measured?
Estimated number of people with three or more heat-related social-vulnerability risk factors, from the Census Bureau's experimental Community Resilience Estimates for Heat. The raw-count companion to the heat-vulnerability rate. Source: US Census Bureau, American Community Survey 5-year estimates (2022).