Henry Smith Farm · Photo: JoeRed · CC BY-SA 3.0On FEMA’s figures, Londonderry Township faces about as much hazard damage per building as the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Londonderry Township gets a B− for hazard risk: higher expected damage per building than 55% of U.S. towns, #802 of 1,037 in Pennsylvania. Most of that expected damage is river and rain flooding (85%). Flood insurance has paid 224 claims here since 1978.
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
What stands out about Londonderry Township’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Londonderry Township 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
Hurricanes
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.
What’s behind Londonderry Township’s grade
River and rain flooding is 85% of the building damage FEMA expects in Londonderry Township, and Londonderry Township’s rate of river and rain flooding damage is higher than 72% of U.S. census tracts. Next is hurricanes at 8% (higher than 80% of U.S. census tracts).
B− #802 of 1,037 in Pennsylvania; higher expected damage per building than 55% of U.S. towns (21,298).
All of Londonderry Township’s residents live in one census tract; the figures are that tract’s.
The typical Pennsylvania town has lower expected damage than 71% of U.S. towns; within the state, Londonderry Township has more expected damage per building than 77% of Pennsylvania towns.
In dollars, FEMA expects about $1.9M a year in losses across Londonderry Township: $1.6M to buildings, the rest to people and crops.
Does Londonderry Township flood? Yes: 224 flood claims since 1978
Every paid claim on a federal flood insurance policy in Londonderry Township, from FEMA’s records: 113.4 per 1,000 homes, more than 97% of the 13,809 U.S. towns with a flood insurance record.
- Tropical Storm Lee80 claims · $3.0M
- Tropical Storm Ivan50 claims · $933K
Londonderry Township isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Dauphin County.1 federal disaster brought FEMA money to Londonderry Township
Disasters that paid out in Londonderry Township itself (aid to households or repair grants to Londonderry Township), newest first, with that year’s flood claims.
- 2004Tropical Depression Ivan2 households applied for aid$2K aid approved50 flood claims paid for it, $933K
Dauphin County has had 17 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.
Old photos of Londonderry Township after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Londonderry Township archive →Londonderry Township and its neighbors
Londonderry Township is 7th of the 9 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Derry Township | A−less damage than 80% | river and rain flooding | 181 |
| West Donegal Township | A−less damage than 78% | river and rain flooding | 2 |
| Lower Swatara Township | A−less damage than 77% | river and rain flooding | 91 |
| Mount Joy Township | B+less damage than 75% | river and rain flooding | 11 |
| Conoy Township | Bless damage than 58% | river and rain flooding | 13 |
| Royalton | B−more damage than 55% | river and rain flooding | 80 |
| Londonderry Township | B−more damage than 55% | river and rain flooding | 224 |
| Newberry Township | C+more damage than 60% | river and rain flooding | 88 |
| Middletown | C−more damage than 82% | river and rain flooding | 340 |
| Goldsboro | — | 981 residents; we grade 1,000+ | |
| Falmouth | — | 521 residents; we grade 1,000+ | |
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.
Get ready for what Londonderry Township faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- 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.
- 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.
- 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.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Londonderry Township
Is Londonderry Township at risk for natural disasters?
On FEMA’s National Risk Index, Londonderry Township has higher expected damage per building than 55% of U.S. towns: B− for hazard risk, #802 of 1,037 in Pennsylvania. Most of the expected damage is river and rain flooding (85%) and hurricanes (8%). 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 Londonderry Township flood?
Flood insurance has paid 224 claims in Londonderry Township since 1978, $5.0M in all, or 113.4 per 1,000 homes, more than 97% of U.S. towns with a flood insurance record. The most claims came from Tropical Storm Lee (80).
Is Londonderry Township 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 Dauphin County, 26% of homes in mapped flood zones carry federal flood insurance, and 1.2% of all homes do.
How much is flood insurance in Londonderry Township?
FEMA’s Community Rating System list shows no discount for Londonderry Township’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 Londonderry Township?
By FEMA money that reached Londonderry Township, Tropical Depression Ivan (2004): 2 households applied for aid, $2K approved. By flood claims, Tropical Storm Lee: 80 paid, $3.0M.
Is Londonderry Township at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (85%), and Londonderry Township’s rate for it is higher than 72% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Londonderry Township.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Londonderry Township’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.