Illinois lightning risk
Cook County has the highest lightning risk in Illinois, scoring 98.2 out of 100 — rated "Very High" by FEMA's National Risk Index. Recorded lightning events across Illinois have decreased 53% over the past five years compared to the prior five-year period.
| # | County | NRI score | Rating |
NOAA events 2016–2026 |
|---|---|---|---|---|
| 1 | Cook County | 98.2 | Very High | 6 |
| 2 | DuPage County | 96.1 | Relatively High | 1 |
| 3 | Lake County | 93.7 | Relatively High | 2 |
| 4 | St. Clair County | 93.7 | Relatively High | 1 |
| 5 | Madison County | 93.2 | Relatively High | 0 |
| 6 | Will County | 89.9 | Relatively High | 7 |
| 7 | Rock Island County | 89.5 | Relatively High | 0 |
| 8 | Winnebago County | 89.2 | Relatively High | 2 |
| 9 | Macoupin County | 88.7 | Relatively High | 0 |
| 10 | Peoria County | 88.6 | Relatively High | 3 |
| 11 | Sangamon County | 88.5 | Relatively High | 4 |
| 12 | Kane County | 88 | Relatively High | 1 |
| 13 | Jackson County | 80.2 | Relatively Moderate | 0 |
| 14 | Champaign County | 79.4 | Relatively Moderate | 0 |
| 15 | Adams County | 76.2 | Relatively Moderate | 1 |
| 16 | Macon County | 75.7 | Relatively Moderate | 1 |
| 17 | McHenry County | 73.5 | Relatively Moderate | 4 |
| 18 | Shelby County | 73 | Relatively Moderate | 0 |
| 19 | Washington County | 72.3 | Relatively Moderate | 0 |
| 20 | LaSalle County | 71.2 | Relatively Moderate | 1 |
| 21 | Boone County | 68.6 | Relatively Moderate | 0 |
| 22 | Livingston County | 68.3 | Relatively Moderate | 1 |
| 23 | Williamson County | 67.7 | Relatively Moderate | 0 |
| 24 | Knox County | 66.4 | Relatively Moderate | 0 |
| 25 | Tazewell County | 65.5 | Relatively Moderate | 1 |
| 26 | Franklin County | 60.5 | Relatively Moderate | 0 |
| 27 | Henry County | 59.6 | Relatively Moderate | 0 |
| 28 | Vermilion County | 59.4 | Relatively Moderate | 1 |
| 29 | Hancock County | 58.2 | Relatively Moderate | 0 |
| 30 | Mercer County | 58.1 | Relatively Moderate | 0 |
| 31 | McLean County | 57.4 | Relatively Moderate | 3 |
| 32 | Montgomery County | 56.8 | Relatively Moderate | 0 |
| 33 | Clinton County | 54.6 | Relatively Low | 0 |
| 34 | Kankakee County | 54 | Relatively Low | 0 |
| 35 | Randolph County | 53.6 | Relatively Low | 0 |
| 36 | Morgan County | 52 | Relatively Low | 0 |
| 37 | Massac County | 51.2 | Relatively Low | 2 |
| 38 | Pike County | 51.1 | Relatively Low | 0 |
| 39 | Whiteside County | 50.4 | Relatively Low | 0 |
| 40 | DeKalb County | 50.1 | Relatively Low | 1 |
| 41 | Marion County | 49.8 | Relatively Low | 0 |
| 42 | Perry County | 49.4 | Relatively Low | 0 |
| 43 | McDonough County | 47.3 | Relatively Low | 1 |
| 44 | Stephenson County | 47.2 | Relatively Low | 1 |
| 45 | Saline County | 46.8 | Relatively Low | 0 |
| 46 | Jefferson County | 46.1 | Relatively Low | 0 |
| 47 | Moultrie County | 45.4 | Relatively Low | 0 |
| 48 | Christian County | 44.5 | Relatively Low | 0 |
| 49 | Coles County | 44.2 | Relatively Low | 2 |
| 50 | Bond County | 43 | Relatively Low | 0 |
| 51 | Fulton County | 43 | Relatively Low | 1 |
| 52 | Fayette County | 41.6 | Relatively Low | 0 |
| 53 | Kendall County | 41.2 | Relatively Low | 1 |
| 54 | Jersey County | 41 | Relatively Low | 0 |
| 55 | Ogle County | 40.1 | Relatively Low | 1 |
| 56 | Monroe County | 39.7 | Relatively Low | 0 |
| 57 | Union County | 38.1 | Relatively Low | 0 |
| 58 | Effingham County | 37.5 | Relatively Low | 0 |
| 59 | Warren County | 36.7 | Relatively Low | 0 |
| 60 | Logan County | 36.5 | Relatively Low | 3 |
| 61 | Bureau County | 36.3 | Relatively Low | 1 |
| 62 | Douglas County | 34.8 | Relatively Low | 0 |
| 63 | White County | 34.5 | Relatively Low | 0 |
| 64 | Johnson County | 33.8 | Relatively Low | 0 |
| 65 | Henderson County | 33.2 | Relatively Low | 0 |
| 66 | Iroquois County | 33.1 | Relatively Low | 0 |
| 67 | Lawrence County | 29.2 | Relatively Low | 0 |
| 68 | Lee County | 28.8 | Relatively Low | 0 |
| 69 | Richland County | 26.8 | Relatively Low | 0 |
| 70 | Menard County | 26 | Relatively Low | 0 |
| 71 | Greene County | 25.1 | Relatively Low | 0 |
| 72 | Clay County | 24 | Relatively Low | 1 |
| 73 | Edgar County | 23.2 | Very Low | 0 |
| 74 | Wayne County | 23.2 | Very Low | 0 |
| 75 | Jo Daviess County | 22.7 | Very Low | 1 |
| 76 | Clark County | 22.6 | Very Low | 1 |
| 77 | Crawford County | 22.6 | Very Low | 0 |
| 78 | De Witt County | 21 | Very Low | 0 |
| 79 | Woodford County | 20.8 | Very Low | 2 |
| 80 | Schuyler County | 19.1 | Very Low | 1 |
| 81 | Grundy County | 18.4 | Very Low | 0 |
| 82 | Carroll County | 18 | Very Low | 0 |
| 83 | Marshall County | 17.2 | Very Low | 0 |
| 84 | Hardin County | 17.1 | Very Low | 1 |
| 85 | Mason County | 16.8 | Very Low | 0 |
| 86 | Alexander County | 16.7 | Very Low | 0 |
| 87 | Cass County | 16.6 | Very Low | 0 |
| 88 | Piatt County | 16.6 | Very Low | 0 |
| 89 | Ford County | 15.8 | Very Low | 1 |
| 90 | Wabash County | 15.2 | Very Low | 0 |
| 91 | Pulaski County | 15.1 | Very Low | 0 |
| 92 | Gallatin County | 14.8 | Very Low | 1 |
| 93 | Cumberland County | 14 | Very Low | 0 |
| 94 | Hamilton County | 12.3 | Very Low | 0 |
| 95 | Brown County | 12 | Very Low | 0 |
| 96 | Jasper County | 11.4 | Very Low | 0 |
| 97 | Edwards County | 11 | Very Low | 0 |
| 98 | Calhoun County | 10.3 | Very Low | 0 |
| 99 | Stark County | 8.7 | Very Low | 0 |
| 100 | Pope County | 8.2 | Very Low | 0 |
| 101 | Putnam County | 7.2 | Very Low | 0 |
| 102 | Scott County | 6 | Very Low | 0 |
Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.
Lightning risk nationally:
Other hazard risks in Illinois:
Frequently asked questions
What is the highest lightning risk county in Illinois?
Cook County, IL has the highest lightning risk in Illinois, with a FEMA National Risk Index score of 98.2 out of 100 (rated "Very High").
How many counties in Illinois are rated Very High for lightning risk?
1 of 102 scored Illinois counties are rated "Very High" for lightning risk by FEMA's National Risk Index.
What causes lightning risk in Illinois?
Lightning risk reflects expected annual losses from cloud-to-ground strikes, which ignite building fires, damage electrical systems, and cause fatalities. Florida consistently leads the US in lightning density. High scores also appear across the Gulf Coast, Southeast, and central Plains, where afternoon convective storms are most frequent in summer months.