Heat Wave Risk by State & County

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 →

Heat Wave Risk by State

#StateExpected Ann. LossAvg. ScoreRatingCounties Rated
1Arizona$1.18B
85.1
Very High 15 of 15
2Texas$797M
53.1
Medium 254 of 254
3Missouri$711M
78.1
High 115 of 115
4California$378M
75.1
High 58 of 58
5Pennsylvania$365M
48.4
Medium 67 of 67
6Illinois$359M
66.6
High 102 of 102
7Nevada$305M
44.8
Medium 17 of 17
8New York$270M
50.5
Medium 62 of 62
9Oklahoma$241M
70.1
High 77 of 77
10Florida$165M
68.5
High 67 of 67
11New Jersey$147M
89.8
Very High 21 of 21
12Arkansas$145M
71.6
High 75 of 75
13Maryland$140M
72.8
High 24 of 24
14Louisiana$140M
74.9
High 64 of 64
15Ohio$119M
54.0
Medium 88 of 88
16Kansas$105M
38.7
Low 105 of 105
17Minnesota$103M
42.9
Medium 87 of 87
18Washington$99M
63.9
High 39 of 39
19Georgia$97M
48.1
Medium 159 of 159
20Tennessee$95M
40.8
Medium 95 of 95
21North Carolina$94M
51.3
Medium 100 of 100
22Alabama$91M
69.8
High 67 of 67
23Wisconsin$89M
52.3
Medium 72 of 72
24Mississippi$87M
69.0
High 82 of 82
25Virginia$84M
35.7
Low 133 of 133
26Michigan$81M
34.8
Low 83 of 83
27Indiana$75M
49.3
Medium 92 of 92
28Oregon$71M
57.1
Medium 36 of 36
29Kentucky$68M
46.3
Medium 120 of 120
30Iowa$61M
41.8
Medium 99 of 99
31South Carolina$54M
69.8
High 46 of 46
32District of Columbia$40M
99.2
Very High 1 of 1
33Massachusetts$38M
65.5
High 14 of 14
34Utah$34M
44.8
Medium 29 of 29
35Idaho$33M
44.3
Medium 44 of 44
36Nebraska$32M
23.4
Low 93 of 93
37New Mexico$23M
42.9
Medium 33 of 33
38West Virginia$19M
31.0
Low 55 of 55
39Connecticut$18M
68.7
High 9 of 9
40Colorado$13M
18.5
Very Low 64 of 64
41Delaware$12M
90.8
Very High 3 of 3
42Rhode Island$10M
54.5
Medium 5 of 5
43South Dakota$10M
22.9
Low 66 of 66
44Montana$7M
21.4
Low 56 of 56
45New Hampshire$6M
49.0
Medium 10 of 10
46Vermont$6M
38.6
Low 14 of 14
47North Dakota$3M
13.5
Very Low 53 of 53
48Maine$3M
24.9
Low 16 of 16
49Wyoming$471K
7.9
Very Low 23 of 23
50Hawaii$0
0.0
Very Low 5 of 5
51Alaska$0
0.0
Very Low 30 of 30

States ranked by total expected annual heat wave losses; the average score is the mean over all counties, counting unrated counties as zero.

Riskiest Counties for Heat Wave

#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.