State disaster-history atlas

Illinois disaster history

Compare federal administrative declarations and NOAA county-coded observed-event reports across 102 Illinois county equivalents. The source-specific distributions and medians below use the statewide official-source datasets, with 1 detailed county profile available to explore.

Data updated Aug 21, 2026 · Current conditions: Live Dashboard →

State baselines by official source

Each median is calculated across every county equivalent using the same source, unit, and coverage period as its linked county profile. Category totals describe records, not severity or losses.

Administrative records

FEMA declaration distribution

OpenFEMA county-designation records show where federal disaster declarations included a county. A single declaration can designate many counties, and declaration decisions do not inventory every physical event.

County median: 12
County sample size: 102
Statewide county records: 1,311

Statewide category distribution
Category	Records	Share of this source
Flood	323	24.6%
Severe storm	297	22.7%
Winter storm	246	18.8%
Biological	204	15.6%
Tornado	139	10.6%
Hurricane	102	7.8%

Coverage: Jan 1, 1964 – Aug 21, 2026
Source updated: Aug 20, 2026
Retrieved by HazardNow: Aug 21, 2026
Completeness for stated rules: complete

Observed-event reports

NOAA observed-event distribution

NOAA Storm Events totals include distinct county-coded records in the comparable all-event era beginning in 1996. Forecast-zone and marine-zone records are excluded from county totals.

County median: 298.5
County sample size: 102
Statewide county records: 37,354

Statewide category distribution
Category	Records	Share of this source
High wind	17,546	47%
Hail	10,498	28.1%
Flood	5,667	15.2%
Tornado	2,580	6.9%
Severe storm	610	1.6%
Lightning	447	1.2%
Wildfire	5	0%
Winter storm	1	0%

Coverage: Jan 1, 1996 – May 31, 2026
Source updated: Aug 19, 2026
Retrieved by HazardNow: Aug 21, 2026
Completeness for stated rules: partial

County profile previews

Preview county record totals and seasonal context here, or use the full directory above. Every profile includes monthly NOAA seasonality, representative records, same-source comparisons, preparedness implications, print and sharing tools, and source disclosures.

County FIPS 17031

Cook County

Unique FEMA declarations: 24
NOAA county-event records: 2,311

NOAA’s largest monthly record count for this profile is 522 in July.

Explore Cook County disaster history

How to read this state atlas

Compare like with like

Compare FEMA declarations only with FEMA declarations, and NOAA county-event records only with NOAA county-event records. Coverage periods must match.

Interpret the median carefully

A county above or below the state median has a different historical record count for the selected official source and coverage period.

Expect reporting limitations

Administrative policy and observation practices change. NOAA finalized records also lag recent event months, and zone-coded events are excluded from county totals.

Browse all state atlases Open the national FEMA heatmap Review data sources