Photo: Ken Gallager at Wikipedia · CC BY-SA 4.0More hazard damage per building is expected in Grantham than in 73% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Grantham gets a C for hazard risk: higher expected damage per building than 73% of U.S. towns, #94 of 126 in New Hampshire. Most of that expected damage is river and rain flooding (92%). Flood insurance has paid 4 claims here since 2006.
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 Grantham 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
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 Grantham’s grade
River and rain flooding is 92% of the building damage FEMA expects in Grantham, and Grantham’s rate of river and rain flooding damage is higher than 86% of U.S. census tracts.
C #94 of 126 in New Hampshire; higher expected damage per building than 73% of U.S. towns (21,298).
All of Grantham’s residents live in one census tract; the figures are that tract’s.
The typical New Hampshire town has higher expected damage than 58% of U.S. towns; within the state, Grantham has more expected damage per building than 74% of New Hampshire towns.
In dollars, FEMA expects about $1.2M a year in losses across Grantham: $1.0M to buildings, the rest to people and crops.
Does Grantham flood? Rarely: 4 flood claims since 2006
Every paid claim on a federal flood insurance policy in Grantham, from FEMA’s records: 1.7 per 1,000 homes, fewer than 65% of the 13,809 U.S. towns with a flood insurance record.
Grantham isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Sullivan County.5 federal disasters brought FEMA money to Grantham
Disasters that paid out in Grantham itself (aid to households or repair grants to the Town of Grantham), newest first, with that year’s flood claims.
- 2013Severe Winter Storm and Snowstorm$6K to the Town of Grantham for repairs
- 2012Hurricane Sandy$4K to the Town of Grantham for repairs
- 2011Tropical Storm Irene$39K to the Town of Grantham for repairs
- 2010Severe Winter Storm$15K to the Town of Grantham for repairs
- 2005Severe Storms and Flooding1 households applied for aid$2K aid approved
Sullivan County has had 27 natural disasters declared by the President since 1953, most often severe storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Grantham after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Grantham archive →Grantham and its neighbors
Grantham is 3rd of the 4 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 |
|---|---|---|---|
| Plainfield | Cmore damage than 71% | river and rain flooding | 1 |
| Springfield | Cmore damage than 73% | river and rain flooding | — |
| Grantham | Cmore damage than 73% | river and rain flooding | 4 |
| Enfield | C−more damage than 82% | river and rain flooding | 3 |
| Croydon | — | 798 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 Grantham 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.
- 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 Grantham
Is Grantham at risk for natural disasters?
On FEMA’s National Risk Index, Grantham has higher expected damage per building than 73% of U.S. towns: C for hazard risk, #94 of 126 in New Hampshire. Most of the expected damage is river and rain flooding (92%). 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 Grantham flood?
Flood insurance has paid 4 claims in Grantham since 2006, $10K in all, or 1.7 per 1,000 homes, fewer than 65% of U.S. towns with a flood insurance record.
Is Grantham 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 Sullivan County, 17% of homes in mapped flood zones carry federal flood insurance, and 0.6% of all homes do.
How much is flood insurance in Grantham?
FEMA’s Community Rating System list shows no discount for Grantham’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 Grantham?
By FEMA money that reached Grantham, Tropical Storm Irene (2011): $39K to the Town of Grantham for repairs.
Is Grantham at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (92%), and Grantham’s rate for it is higher than 86% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Grantham.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Grantham’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.