Riskiest Counties for Heat Wave

Ranked by FEMA National Risk Index heat wave hazard score · code HWAV

Heat Wave risk reflects prolonged periods of extreme heat that threaten health and infrastructure. FEMA's National Risk Index scores each county's heat wave hazard from its expected annual loss, annualized event frequency, and exposed population. Maricopa County, Arizona currently leads the nation with a heat wave score of 100.0 and $958M in expected annual loss. Texas, New York, Arizona account for much of the highest-rated heat wave risk in this dataset.

Read the full heat wave risk guide — how FEMA scores it and how to prepare →

County Rankings

#CountyStateHeat Wave ScoreRatingAnn. Freq.Ann. Loss
1Maricopa CountyAZ
100.0
Very High 19.83 / yr$958M
2Philadelphia CountyPA
100.0
Very High 11.07 / yr$256M
3Dallas CountyTX
99.9
Very High 19.11 / yr$288M
4Clark CountyNV
99.9
Very High 11.75 / yr$295M
5St. Louis CountyMO
99.9
Very High 14.84 / yr$253M
6Cook CountyIL
99.8
Very High 2.90 / yr$193M
7Pima CountyAZ
99.8
Very High 8.09 / yr$133M
8St. Louis CityMO
99.8
Very High 15.05 / yr$172M
9Harris CountyTX
99.7
Very High 14.86 / yr$80M
10Kings CountyNY
99.7
Very High 10.07 / yr$63M
11Queens CountyNY
99.7
Very High 10.59 / yr$58M
12Shelby CountyTN
99.6
High 21.74 / yr$49M
13New York CountyNY
99.6
High 10.22 / yr$41M
14Bronx CountyNY
99.6
High 11.26 / yr$39M
15Tulsa CountyOK
99.6
High 26.26 / yr$76M
16Tarrant CountyTX
99.5
High 19.11 / yr$50M
17Kern CountyCA
99.5
High 7.49 / yr$43M
18Oklahoma CountyOK
99.5
High 18.16 / yr$51M
19Bexar CountyTX
99.4
High 10.32 / yr$39M
20Baltimore CityMD
99.4
High 6.80 / yr$38M
21Washington CountyAR
99.4
High 9.42 / yr$47M
22Los Angeles CountyCA
99.3
High 9.45 / yr$37M
23Miami-Dade CountyFL
99.3
High 6.16 / yr$31M
24Wayne CountyMI
99.3
High 4.32 / yr$32M
25District of ColumbiaDC
99.2
High 6.11 / yr$40M

Showing the top 25 seeded counties for heat wave risk.

Heat Wave Risk by State

DelawareNew JerseyCaliforniaConnecticutArizonaMassachusettsFloridaSouth CarolinaWashingtonNew HampshireNew YorkPennsylvaniaNorth CarolinaOregonLouisianaAlabamaMarylandWisconsinNew MexicoMaineRhode IslandOklahomaArkansasOhioIllinoisTennesseeMississippiMissouriMichiganWest VirginiaTexasNevadaIndianaKentuckyMinnesotaColoradoIowaGeorgiaIdahoWyomingVermontUtahVirginiaMontanaKansasSouth DakotaNebraskaNorth Dakota