Automated baseline from FEMA and NOAA data, release 2026-10.
DeKalb County, IL
Risk-assessment baseline packet. County FIPS 17037. Release 2026-10, data as of 2026-09-30.
Summary
Plan status as of 2026-09-30: Expired on 2026-03-08. Plan: DeKalb County 2021 Hazard Mitigation Plan (FEMA plan 106402), approved 2021-03-09.
Update: FEMA tracker shows a plan awaiting revisions.
Since the plan was approved on 2021-03-09: no new federal declaration.
NOAA Storm Events records since that date: 186 records (data through 2026-06-30).
Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($24,320,665 a year), Cold Wave ($11,580,371) and Tornado ($6,875,541).
The packet's tables are organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B (B1-a to B2-c); the summaries below follow the same order.
14 of the 18 National Risk Index hazards apply here.
Not applicable to this county per NRI, with no federal declaration and no Storm Events record since 1996: avalanche, coastal flooding, tsunami and volcanic activity. That is the evidence for leaving them out of the plan.
Highest expected annual loss (NRI, modeled): Inland Flooding, Cold Wave and Tornado.
Not covered by NRI (local data needed): dam failure (incl. upstream dams); levee failure; flash flood as its own subtype; ice jams; debris flows; erosion (riverine and coastal); land subsidence and sinkholes; expansive soils.
The state hazard mitigation plan also lists hazards for this county; FEMA asks the plan to explain any hazard it leaves out.
Supports FEMA checklist item B1-b Hazard location
Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather: Affects the whole county; national data give no location within it.
Inland Flooding: The FEMA Flood Insurance Rate Map (FIRM) is the required location source for flooding. See the FEMA Flood Map Service Center (https://msc.fema.gov) for this county.
Supports FEMA checklist item B1-c Hazard extent
Storm Events records for 12 of the 20 NOAA event-type groups mapped to the 18 hazards, with the scale, observed range and worst recorded event for each; the others say which local data are needed.
Tornado: EF3 tornado, 2015-04-09, 4.83 mi within this county, 700 yd wide, $8,000,000 property; $0 crops (2015 dollars), 2 direct deaths, 11 direct injuries
Federal declarations for this area: 12 declarations covering 9 separate hazard incidents counted in this packet; each with type, dates and county Public Assistance dollars.
New since the last plan (approved 2021-03-09): none.
2 statewide declarations listed separately.
Hazards with no Storm Events record and no federal declaration are stated as such (8 of 18).
Storm Events history: 640 records (notable ones in the PDF, all of them in the Excel file).
Supports FEMA checklist item B1-e Probability of future events
FEMA annualized frequency (modeled) for each hazard, with a descriptor from a scale defined in the packet.
Historical frequency by intensity band (tornado, hail, wind): 9 bands from Storm Events.
Supports FEMA checklist item B1-f Hazards that vary across jurisdictions
Range of census tract risk scores within the area for 14 of the 18 hazards (23 tracts; rated tracts only).
15 jurisdictions: plan clock, repeat-flood count, Public Assistance dollars and event records naming the place (starting figures from federal data).
County Public Assistance in B1-d also includes applicants filed under the county that are not jurisdictions in this plan (for example state agencies, special districts and nonprofits), so the jurisdiction rows add up to less.
Supports FEMA checklist items B2-a and B2-b Vulnerability and potential impacts
The packet's table gives county-level starting figures; the plan describes impacts for each jurisdiction and its own assets.
Storm Events damage since 2021-03-09: $0 in county-coded records (132 records); $0 reported for the zone (54 zone records). Data through 2026-06-30; nominal dollars.
Local data needed
To gather:
Critical facilities and lifelines per hazard
A problem statement per jurisdiction per hazard
Changes in development in hazard-prone areas since the last approval, or a statement of none (E1-a)
Population 100,385; building value $29,387,863,413 and agriculture value $494,739,891 (total, not at risk).
National Risk Index rating Relatively Low; social vulnerability Relatively Low; community resilience Relatively High.
Supports FEMA checklist item B2-c Repetitive loss properties
Repetitive-loss properties, FMA definition (44 CFR 77.2): 3 repetitive loss, 7 severe repetitive loss. NFIP insurance definition: 29 and 5.
Mitigated 1; insured 10; NFIP data as of 2026-08-02. Counts by occupancy group and for each jurisdiction are in the packet.
Releases
2026-10 (this release)
Each release is dated; this is release 2026-10. It was first published 2026-09-30; its files do not change. Later releases will be listed here with what changed between them. All releases.
Cite this
Hazard Plain (2026). DeKalb County, IL: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 17037). Automated baseline. https://hazardplain.org/il/17037/ Built from FEMA OpenFEMA, the FEMA National Risk Index and NOAA NCEI Storm Events; source versions in the packet's Sources list.