Heat wave risk by county
Long stretches of unusually hot weather. Heat causes more US weather deaths than any other hazard, mostly among older adults and people without air conditioning.
Highest expected losses
| # | County | Rating | A year |
|---|---|---|---|
| 1 | Maricopa County, AZ | $958M | |
| 2 | Clark County, NV | $295M | |
| 3 | Dallas County, TX | $288M | |
| 4 | Philadelphia County, PA | $256M | |
| 5 | St. Louis County, MO | $253M | |
| 6 | Cook County, IL | $193M | |
| 7 | St. Louis City, MO | $172M | |
| 8 | Pima County, AZ | $133M | |
| 9 | Harris County, TX | $80M | |
| 10 | Tulsa County, OK | $76M | |
| 11 | Kings County, NY | $63M | |
| 12 | Queens County, NY | $58M | |
| 13 | Oklahoma County, OK | $51M | |
| 14 | Tarrant County, TX | $50M | |
| 15 | Shelby County, TN | $49M |
Big counties lead this list partly because they have more people and buildings at risk.
Highest per resident
| # | County (100,000+ people) | Per person a year |
|---|---|---|
| 1 | St. Louis City, MO | $572 |
| 2 | St. Louis County, MO | $252 |
| 3 | Maricopa County, AZ | $217 |
| 4 | Washington County, AR | $192 |
| 5 | Cochise County, AZ | $178 |
| 6 | Philadelphia County, PA | $160 |
| 7 | Clark County, NV | $130 |
| 8 | Pima County, AZ | $128 |
| 9 | Tulsa County, OK | $113 |
| 10 | Dallas County, TX | $111 |
Expected yearly loss divided by population. A fairer way to compare places of different size.
Lowest risk among large counties
| # | County (250,000+ people) | Rating | Per person a year |
|---|---|---|---|
| 1 | Buncombe County, NC | under $1 | |
| 2 | Erie County, PA | under $1 | |
| 3 | Washoe County, NV | $1 | |
| 4 | Arapahoe County, CO | $2 | |
| 5 | Denver County, CO | $2 | |
| 6 | Westmoreland County, PA | $2 | |
| 7 | Douglas County, CO | $2 | |
| 8 | Jefferson County, CO | $2 | |
| 9 | Santa Barbara County, CA | $2 | |
| 10 | Larimer County, CO | $2 |
How ratings are spread
The lists above show only the top counties, so they are all rated high. Across all 3,062 rated counties, most are Low or Very Low:
How to prepare
- Check that cooling works before summer.
- Know where the nearest cooling center is.
- Check on older neighbors during long hot spells.
States where it is most often the top hazard
Common questions
Which US county has the highest heat wave risk?
Maricopa County, AZ has the highest expected yearly heat wave losses in FEMA's National Risk Index, about $958 million a year. Clark County, NV is second at $295 million.
How many counties face heat wave risk?
FEMA rates heat wave in 3,062 of 3,144 counties in the 50 states and DC. 11 are rated Very High and 98 Relatively High.
Is heat wave covered by home insurance?
Usually yes for damage to the home, but check deductibles. Some states and insurers use separate wind, hail or hurricane deductibles.
Other hazards
Source: FEMA National Risk Index (December 2025). Expected annual loss is FEMA's long-run estimate of yearly damage to buildings, people and farm output, in dollars.