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A−Hazard risk
Natural hazards in Mercersburg · FEMA

Less hazard damage per building is expected in Mercersburg than in 78% of U.S. towns, mostly from river and rain flooding

On FEMA’s National Risk Index, Mercersburg gets an A− for hazard risk: lower expected damage per building than 78% of U.S. towns. Most of that expected damage is river and rain flooding (83%). Flood insurance has paid 1 claim here since 1989.

River and rain flooding 83%Hurricanes 10%Earthquakes 3%

Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded

less than 78%of U.S. townsLess damageMoreExpected yearly damage per dollar of building, vs. the 21,298 U.S. towns we grade
Hazard risk
A−
in Pennsylvania · lower than 78% of U.S. towns
Main hazard
River and rain flooding
83% of expected building damage
Flood claims
1
paid since 1989 · $797
Disasters paid out here
1
of 16 declared for Franklin County
By hazard

What Mercersburg faces

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

River and rain flooding

83%of expected building damage
About average · lower than 56% of U.S. census tracts
Recorded about 2 times a year in the area

Hurricanes

10%of expected building damage
Above average · higher than 78% of U.S. census tracts
Recorded about once every 14 years in the area
Smaller shares here
 Earthquakes Tornadoes Hail Strong wind Wildfire Ice storms Lightning Winter storms Cold waves Heat waves Landslides
FEMA models no building damage here
Coastal floodingAvalanchesTsunamisVolcanic activity

Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.

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

What’s behind Mercersburg’s grade

River and rain flooding is 83% of the building damage FEMA expects in Mercersburg, and Mercersburg’s rate of river and rain flooding damage is lower than 56% of U.S. census tracts. Next is hurricanes at 10% (higher than 78% of U.S. census tracts).

Where Mercersburg sits
Mercersburg
Least damageMiddleMost damage

A− lower expected damage per building than 78% of U.S. towns (21,298).

All of Mercersburg’s residents live in one census tract; the figures are that tract’s.

What drives the damage to buildings
River and rain flooding83%Hurricanes10%Earthquakes3%Everything else5%

In dollars, FEMA expects about $398K a year in losses across Mercersburg: $322K to buildings, the rest to people and crops.

Shared tract.All of Mercersburg’s 1,507 residents (2020 census) live in one census tract, which it shares with Peters township (4,462 residents) and Fort Loudon CDP (895 residents). FEMA publishes its model by tract, so the rate and the hazard mix are the tract’s, the same for all of them. The flood claims below are the town’s own.
A shared figure. The grade describes the whole tract, not each street in it, and FEMA’s model is an average year for today’s buildings, not a record: the claims below are the record.

How TownRatings grades hazard risk →

Flood insurance claims

Does Mercersburg flood? Rarely: 1 flood claim since 1989

Every paid claim on a federal flood insurance policy in Mercersburg, from FEMA’s records: 1.2 per 1,000 homes, fewer than 75% of the 13,809 U.S. towns with a flood insurance record.

Paid flood claims, by year
1989: 1 claim1990: 0 claims1991: 0 claims1992: 0 claims1993: 0 claims1994: 0 claims1995: 0 claims1996: 0 claims1997: 0 claims1998: 0 claims1999: 0 claims2000: 0 claims2001: 0 claims2002: 0 claims2003: 0 claims2004: 0 claims2005: 0 claims2006: 0 claims2007: 0 claims2008: 0 claims2009: 0 claims2010: 0 claims2011: 0 claims2012: 0 claims2013: 0 claims2014: 0 claims2015: 0 claims2016: 0 claims2017: 0 claims2018: 0 claims2019: 0 claims2020: 0 claims2021: 0 claims2022: 0 claims2023: 0 claims2024: 0 claims2025: 0 claims2026: 0 claims1989
19892026
1
paid claims since 1989
$797
paid to owners
0
homes flooded more than once
$797
average claim
of homes in flood zones are insured
of all homes are insured
No community discount

Mercersburg isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.

Insurance rates: Franklin County.
Disasters

1 federal disaster brought FEMA money to Mercersburg

Disasters that paid out in Mercersburg itself (aid to households or repair grants to the Borough of Mercersburg), newest first, with that year’s flood claims.

  1. 2006Severe Storms, Flooding, and Mudslides3 households applied for aid$14K aid approved
Disasters declared, by decade
Paid out in MercersburgFranklin County only

Franklin County has had 16 natural disasters declared by the President since 1953, most often floods, then winter storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.

Were you here?

Old photos of Mercersburg after a storm or flood belong in the town’s history. Add one, or share what you remember below.

Add to the Mercersburg archive →
Next door

Mercersburg and its neighbors

Mercersburg is 2nd of the 3 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.

Peters Township: hazard risk A−Montgomery Township: hazard risk A−Peters TownshipMontgomery TownshipMercersburg
Lowest fifthSecondMiddleFourthHighest fifth
TownHazard riskMostly (buildings)Flood claims
Peters TownshipA−less damage than 78%river and rain flooding19
MercersburgA−less damage than 78%river and rain flooding1
Montgomery TownshipA−less damage than 78%river and rain flooding1

Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.

Be ready

Get ready for what Mercersburg faces

A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.

When the river rises
  • Turn around at flooded roads: a foot of moving water can carry off a car.
  • Flood insurance usually takes 30 days to start, so buy it before the forecast.
  • Keep papers and medicines up high, in a grab-and-go bag.
More from Ready.gov ↗
Hurricane season
  • The season runs June through November and peaks from mid-August to mid-October.
  • Bring in porch furniture and anything the wind can throw.
  • Fill the gas tank and charge phones before the storm arrives.
More from Ready.gov ↗
Before you buy or rent
  • Look up the address on FEMA’s flood map.
  • Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
  • Get a flood insurance quote early: policies usually start 30 days after you buy.
When a storm is coming
Forecast and alertsWeather →911, the nearest ERSafety →

Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.

Questions about natural hazards in Mercersburg

Is Mercersburg at risk for natural disasters?

On FEMA’s National Risk Index, Mercersburg has lower expected damage per building than 78% of U.S. towns: A− for hazard risk. Most of the expected damage is river and rain flooding (83%) and hurricanes (10%). The figures are for the one census tract the town shares with its neighbors. This is FEMA’s model of an average year for today’s buildings, not a forecast.

Does Mercersburg flood?

Flood insurance has paid 1 claim in Mercersburg since 1989, $797 in all, or 1.2 per 1,000 homes, fewer than 75% of U.S. towns with a flood insurance record.

Is Mercersburg in a flood zone?

Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Franklin County, 20% of homes in mapped flood zones carry federal flood insurance, and 0.4% of all homes do.

How much is flood insurance in Mercersburg?

FEMA’s Community Rating System list shows no discount for Mercersburg’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.

What was the biggest storm in Mercersburg?

By FEMA money that reached Mercersburg, Severe Storms, Flooding, and Mudslides (2006): 3 households applied for aid, $14K approved.

Is Mercersburg at risk from river and rain flooding?

It is the largest share of the building damage FEMA expects here (83%), and Mercersburg’s rate for it is lower than 56% of U.S. census tracts.

Storm stories

Memories, warnings and help from neighbors in Mercersburg.

Town Square →
Start the conversation

Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Mercersburg’s residents lived in the 2020 census; 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. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.