Tornado Risk in Montana

All Montana counties ranked by FEMA National Risk Index tornado score

Tornado risk — violently rotating columns of air capable of catastrophic local damage — is rated for 56 of 56 Montana counties in FEMA's National Risk Index. Roosevelt County carries the state's highest tornado score at 32.1, with $322K in expected annual tornado losses.

No Montana county reaches the High band for tornado, and expected annual losses from tornado total roughly $4M statewide. The full ranking below links to each county's complete 18-hazard risk profile.

County Rankings — Tornado

#CountyTornado ScoreRatingAnn. Freq.Ann. Loss
1 Roosevelt County
32.1
Low 0.25 / yr $322K
2 Yellowstone County
28.9
Low 0.15 / yr $560K
3 Richland County
27.0
Low 0.23 / yr $561K
4 Dawson County
25.1
Very Low 0.23 / yr $335K
5 Cascade County
20.8
Very Low 0.13 / yr $280K
6 Carbon County
17.1
Very Low 0.11 / yr $141K
7 Gallatin County
16.7
Very Low 0.06 / yr $259K
8 Custer County
16.2
Very Low 0.26 / yr $126K
9 Sheridan County
16.1
Very Low 0.14 / yr $135K
10 Fergus County
15.7
Very Low 0.38 / yr $149K
11 Valley County
14.6
Very Low 0.43 / yr $134K
12 Big Horn County
12.1
Very Low 0.32 / yr $54K
13 Chouteau County
11.9
Very Low 0.25 / yr $73K
14 McCone County
10.8
Very Low 0.28 / yr $84K
15 Fallon County
10.5
Very Low 0.18 / yr $98K
16 Missoula County
10.1
Very Low 0.04 / yr $101K
17 Rosebud County
10.1
Very Low 0.29 / yr $36K
18 Silver Bow County
9.8
Very Low 0.02 / yr $74K
19 Ravalli County
9.1
Very Low 0.03 / yr $51K
20 Lewis and Clark County
8.9
Very Low 0.08 / yr $62K
21 Wibaux County
8.7
Very Low 0.11 / yr $68K
22 Prairie County
8.7
Very Low 0.15 / yr $38K
23 Park County
8.3
Very Low 0.05 / yr $51K
24 Hill County
8.3
Very Low 0.09 / yr $39K
25 Musselshell County
8.1
Very Low 0.15 / yr $34K
26 Daniels County
7.9
Very Low 0.11 / yr $56K
27 Phillips County
7.8
Very Low 0.30 / yr $29K
28 Carter County
7.6
Very Low 0.39 / yr $53K
29 Judith Basin County
7.3
Very Low 0.16 / yr $41K
30 Powder River County
7.3
Very Low 0.27 / yr $45K
31 Beaverhead County
6.8
Very Low 0.17 / yr $24K
32 Blaine County
6.7
Very Low 0.18 / yr $19K
33 Stillwater County
6.6
Very Low 0.07 / yr $44K
34 Lincoln County
6.0
Very Low 0.04 / yr $18K
35 Wheatland County
5.8
Very Low 0.11 / yr $20K
36 Jefferson County
5.7
Very Low 0.05 / yr $27K
37 Deer Lodge County
5.5
Very Low 0.02 / yr $21K
38 Meagher County
5.2
Very Low 0.14 / yr $19K
39 Broadwater County
5.1
Very Low 0.04 / yr $19K
40 Teton County
5.0
Very Low 0.06 / yr $22K
41 Sanders County
4.7
Very Low 0.04 / yr $10K
42 Flathead County
4.6
Very Low 0.07 / yr $19K
43 Pondera County
4.5
Very Low 0.04 / yr $10K
44 Garfield County
4.2
Very Low 0.34 / yr $16K
45 Madison County
4.1
Very Low 0.09 / yr $16K
46 Toole County
3.8
Very Low 0.04 / yr $10K
47 Sweet Grass County
3.8
Very Low 0.06 / yr $16K
48 Golden Valley County
3.8
Very Low 0.10 / yr $11K
49 Glacier County
3.7
Very Low 0.04 / yr $6K
50 Liberty County
3.5
Very Low 0.05 / yr $8K
51 Lake County
3.3
Very Low 0.03 / yr $7K
52 Granite County
2.7
Very Low 0.03 / yr $5K
53 Petroleum County
2.5
Very Low 0.11 / yr $5K
54 Powell County
2.2
Very Low 0.05 / yr $3K
55 Treasure County
1.9
Very Low 0.05 / yr $4K
56 Mineral County
1.3
Very Low 0.02 / yr $1K

56 Montana counties with measurable tornado risk. See the national tornado ranking or all Montana counties by overall risk.

Frequently Asked Questions

Which Montana county has the highest tornado risk?

Roosevelt County has the highest FEMA tornado risk score in Montana at 32.1 (Low), with $322K in expected annual losses and about 0.25 events per year.

How many Montana counties face significant tornado risk?

56 Montana counties record measurable tornado risk in FEMA's National Risk Index; 0 of them are rated High or Very High.

Other Hazards in Montana

Avalanche Cold Wave Drought Earthquake Hail Heat Wave Ice Storm Riverine Flood Landslide Lightning Strong Wind Volcanic Activity Wildfire Winter Weather