Natural hazards · Johnston

Johnston, IL natural hazards

Most of the natural-hazard damage FEMA expects in Johnston comes from earthquakes, and overall the risk is high for a U.S. community. Flood insurance has paid 4 claims here since 1996. 1 federal disaster brought FEMA money into town.

FEMA National Risk Index, December 2025 · OpenFEMA claims, aid & declarations

Expected damage

How exposed is Johnston?

High

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Johnston to be higher than in 79% of U.S. communities, mostly from earthquakes and inland flooding.

Earthquakes35%Inland flooding24%Strong wind13%Cold waves11%Tornadoes8%Heat waves6%Everything else4%

By hazard

What Johnston faces

Each hazard’s share of the damage FEMA expects here, and how that compares with the rest of the country.

Earthquakes

35% of expected damage

Well above average · higher than 88% of U.S. places

Inland flooding

24% of expected damage

Above average · higher than 59% of U.S. places

Recorded about 2 times a year in the area

Strong wind

13% of expected damage

Well above average · among the top 1% of U.S. places

Recorded about 4 times a year in the area

Cold waves

11% of expected damage

Well below average · higher than 20% of U.S. places

Recorded about once a year in the area

Tornadoes

8% of expected damage

Below average · higher than 49% of U.S. places

Recorded about once every 66 years in the area

Heat waves

6% of expected damage

Below average · higher than 43% of U.S. places

Recorded about 10 times a year in the area

Lower here

HurricanesHailIce stormsWinter weatherWildfireLandslidesLightningDrought

Not a risk here

Coastal floodingAvalanchesTsunamisVolcanic activity

Flood risk changes street by street. Check a specific address on FEMA’s flood map, and ask about flood insurance before you buy.

Flood insurance claims

Does Johnston flood?

Every paid claim on a federal flood insurance policy in Johnston, from FEMA’s records.

4paid claims since 1996

$14Kpaid to owners

0homes flooded more than once

19962026

Biggest named events

March storm: 1 claim, $907

of homes in flood zones
are insured

of all homes
are insured

No community discount. Johnston isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.

Insurance rates: Williamson County.

Disasters that hit Johnston

1 federal disaster brought FEMA money here

Disasters the President declared that paid out in Johnston itself: aid to households, or repair grants to the City of Johnston.

Brought FEMA money into JohnstonDeclared for Williamson County only

2011

Severe Storms and Flooding

18 households applied for aid $106K aid approved

Williamson County has had 7 natural disasters declared since 1953, most often severe storms and tornadoes.

About these numbers

How to read this page

An average, not a forecastFEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.

Compared by rate“Higher than N%” compares yearly damage as a share of what’s here, so a big city isn’t rated riskier just for having more buildings. Johnston is smaller than a census tract, so it shares the figures of the tract around its center.

Money that reached townFlood claims are matched to Johnston’s own flood-insurance community; household aid to the registrant’s city; repair grants to the City of Johnston. FEMA’s model follows property values, so a place that recently lost many homes can rate lower than it feels.

Sources: FEMA National Risk Index (December 2025); OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Census tracts: U.S. Census Bureau.