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Mercer County, Missouri

Natural disaster risk, federal disaster history and flood insurance facts.

Very Low overall risk
111th of 115highest risk in Missouri
$4Mexpected losses a year
18federal declarations
Photo: U.S. Geological Survey, public domain

Mercer County, Missouri has a very low overall risk from natural hazards in FEMA's National Risk Index. Its risk score is lower than 88% of US counties. It ranks 111th of 115 counties in Missouri. The costliest hazards here are inland flooding, tornadoes and drought. FEMA estimates about $4.0 million a year in expected losses, or roughly $1,118 per resident. Since 1973 it has been included in 18 federal disaster or emergency declarations for natural events (13 major disasters). The most recent was in August 2026 (severe storms, straight-line winds, tornadoes and flooding). No homes here carry federal flood insurance.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Mercer County

$1.6 million a yearExpected losses. Damaging events about once every 3 years.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.
$754,659 a yearExpected losses. Damaging events about once every 4 years.
  • Pick a shelter spot: a basement, or an inside room on the lowest floor with no windows.
  • Turn on emergency alerts on your phone and keep a weather radio.

Drought

Moderate
$587,183 a yearExpected losses. Damaging events about 12 times a year.
  • Check local water restrictions.
  • Choose drought-tolerant plants.
HazardRatingScoreExpected loss a year
Inland floodingVery Low17.9
$2M
TornadoLow44.0
$755K
DroughtModerate77.4
$587K
Cold waveLow34.8
$389K
Heat waveLow46.3
$230K
HailLow42.5
$145K
Strong windLow20.5
$138K
WildfireVery Low48.3
$32K
LightningVery Low9.4
$23K
EarthquakeVery Low17.2
$16K
Winter weatherVery Low17.1
$11K
LandslideLow79.0
$11K
Ice stormVery Low9.1
$3K
HurricaneVery Low11.4
$2K

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is relatively high and community resilience is very low in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Mercer County. 2020s bar runs to November 2026.

By type

Severe Storm11
Severe Ice Storm3
Flood2
Drought1
Hurricane1

Most recent

Aug 3, 2026Severe Storms, Straight-Line Winds, Tornadoes, and FloodingMajor disaster
Jul 9, 2019Severe Storms, Tornadoes, and FloodingMajor disaster
Oct 31, 2014Severe Storms, Tornadoes, Straight-Line Winds, and FloodingMajor disaster
Feb 3, 2011Severe Winter StormEmergency
Aug 17, 2010Severe Storms, Flooding, and TornadoesMajor disaster
Jan 30, 2009Severe Winter StormEmergency
Jun 25, 2008Severe Storms and FloodingMajor disaster
Dec 27, 2007Severe Winter StormsMajor disaster
Dec 12, 2007Severe Winter StormsEmergency
Jun 11, 2007Severe Storms and FloodingMajor disaster
Show all 18
Sep 10, 2005Hurricane Katrina EvacuationEmergency
Jun 11, 2004Severe Storms, Tornadoes, and FloodingMajor disaster
May 6, 2002Severe Storms, Tornadoes and FloodingMajor disaster
Jun 2, 1995Severe Storms, Tornadoes, Hail, FloodingMajor disaster
Jul 9, 1993Severe Storms & FloodingMajor disaster
Sep 24, 1976DroughtEmergency
Nov 1, 1973Severe Storms & FloodingMajor disaster
Apr 19, 1973Heavy Rains, Tornadoes & FloodingMajor disaster

Missouri also had 5 statewide declarations that did not name single counties.

Storm history since 1955

Tornado risk by county ›

The National Weather Service has logged 187 storm reports in Mercer County since 1955, with 0 deaths and 1 injury and about $525,030 in reported damage. The strongest on record here was an F4 tornado on April 21, 1973.

17tornadoes
89hail reports, largest 3 inches
67damaging thunderstorm winds
13floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Apr 21, 1973F4–1 / 0
Sep 26, 1959F2–0 / 0
Sep 26, 1959F2–0 / 0
Apr 16, 1960F2–0 / 0
Apr 16, 1960F2–0 / 0

Most damaging storms

DateTypeNearDamage
Apr 21, 1973Tornado–$250K
Jun 15, 1958Tornado–$25K
May 20, 1959Tornado–$25K
Sep 26, 1959Tornado–$25K
Sep 26, 1959Tornado–$25K
Jun 4, 1960Tornado–$25K

Source: NOAA Storm Events Database, county-based reports through Sep 17, 2025. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Mercer County

Check your address flood zone ›
0%of homes have federal flood insurance (0 policies)
0%of homes in mapped high-risk flood zones are insured
$0paid on 0 flood claims since 1978
n/acostliest year

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Mercer County

$104,900median home value (Missouri $230,300, US $332,700)
1970median year homes were built (Missouri 1978, US 1980)
67%of homes built before 1980, before many modern wind, quake and flood building rules
6.4%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 1,902 housing units.

Compare in Missouri

All 115 ›
Largest countiesOverall riskTop hazard
St. Louis CountyHighHeat wave
Jackson CountyHighInland flooding
St. Charles CountyModerateInland flooding
St. Louis CityHighHeat wave
Greene CountyModerateInland flooding
Clay CountyModerateInland flooding
Jefferson CountyModerateInland flooding
Boone CountyModerateInland flooding

Neighboring counties

CountyOverall riskDeclarations
Grundy CountyVery Low20
Harrison CountyVery Low17
Decatur County, IAVery Low12
Wayne County, IAVery Low13
Sullivan CountyVery Low23
Putnam CountyVery Low17

Common questions about Mercer County

What is the biggest natural hazard in Mercer County?

Inland flooding has the highest expected yearly losses in Mercer County, about $1.6 million a year in FEMA's estimate. Tornado is second at $754,659.

How many federal disasters has Mercer County had?

Mercer County has been included in 18 federal disaster or emergency declarations for natural events since 1973, including 13 major disasters. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding in August 2026.

Is Mercer County a high-risk place to live?

Its overall rating is Very Low, 111th highest of 115 in Missouri. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Mercer County?

Standard home insurance does not cover flooding. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Mercer County had?

NOAA records list 17 tornadoes in Mercer County since 1950. The strongest was an F4 tornado on April 21, 1973. The weather service has also logged 89 hail reports and 13 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.