Photo: Ken Gallager at en.wikipedia · Public domainFEMA expects about as much hazard damage per building in Alton as in the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Alton gets a C+ for hazard risk: higher expected damage per building than 55% of U.S. towns, #59 of 126 in New Hampshire. Most of that expected damage is river and rain flooding (76%), then hurricanes (15%). Flood insurance has paid 4 claims here since 1981.
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 Alton 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 Alton’s grade
River and rain flooding is 76% of the building damage FEMA expects in Alton, and Alton’s rate of river and rain flooding damage is higher than 66% of U.S. census tracts. Ice storms add 4%, at a rate in the top 4% of U.S. census tracts.
C+ #59 of 126 in New Hampshire; higher expected damage per building than 55% of U.S. towns (21,298).
Alton’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
The typical New Hampshire town has higher expected damage than 58% of U.S. towns; within the state, Alton has less expected damage per building than 54% of New Hampshire towns.
In dollars, FEMA expects about $2.4M a year in losses across Alton: $2.0M to buildings, the rest to people and crops.
Does Alton flood? Rarely: 4 flood claims since 1981
Every paid claim on a federal flood insurance policy in Alton, from FEMA’s records: 0.9 per 1,000 homes, fewer than 81% of the 13,809 U.S. towns with a flood insurance record.
Alton isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Belknap County.13 federal disasters brought FEMA money to Alton
Disasters that paid out in Alton itself (aid to households or repair grants to the Town of Alton), newest first, with that year’s flood claims.
- 2023Severe Storms and Flooding$536K to the Town of Alton for repairs
- 2022Severe Storm and Flooding$225K to the Town of Alton for repairs
- 2017Severe Storm and Flooding$65K to the Town of Alton for repairs
- 2013Severe Winter Storm and Snowstorm$26K to the Town of Alton for repairs
- 2012Hurricane Sandy$5K to the Town of Alton for repairs
- 2011Tropical Storm Irene$77K to the Town of Alton for repairs
Show all 13
- 2008Severe Winter Storm$38K to the Town of Alton for repairs
- 2008Severe Storms, Tornado, and Flooding$129K to the Town of Alton for repairs
- 2007Severe Storms and Flooding5 households applied for aid$5K aid approved$655K to the Town of Alton for repairs1 flood claim paid that year
- 2006Severe Storms and Flooding6 households applied for aid$1K aid approved$105K to the Town of Alton for repairs
- 2005Severe Storms and Flooding1 households applied for aid$31K to the Town of Alton for repairs
- 2005Record And/or Near Record Snow$14K to the Town of Alton for repairs
- 2003Snow$17K to the Town of Alton for repairs
Belknap County has had 23 natural disasters declared by the President since 1953, most often severe storms, then winter storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Alton after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Alton archive →Alton and its neighbors
Alton is 5th of the 8 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 |
|---|---|---|---|
| Gilford | B+less damage than 68% | river and rain flooding | 4 |
| New Durham | Bless damage than 59% | river and rain flooding | 2 |
| Wolfeboro | B−less damage than 54% | river and rain flooding | 4 |
| Gilmanton | B−more damage than 54% | river and rain flooding | 1 |
| Alton | C+more damage than 55% | river and rain flooding | 4 |
| Tuftonboro | C+more damage than 58% | river and rain flooding | 1 |
| Barnstead | Cmore damage than 68% | river and rain flooding | 5 |
| Farmington | C−more damage than 82% | river and rain flooding | 8 |
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 Alton 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 Alton
Is Alton at risk for natural disasters?
On FEMA’s National Risk Index, Alton has higher expected damage per building than 55% of U.S. towns: C+ for hazard risk, #59 of 126 in New Hampshire. Most of the expected damage is river and rain flooding (76%) and hurricanes (15%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Alton flood?
Flood insurance has paid 4 claims in Alton since 1981, $32K in all, or 0.9 per 1,000 homes, fewer than 81% of U.S. towns with a flood insurance record. 1 properties have flooded more than once.
Is Alton 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 Belknap County, 0.6% of all homes carry federal flood insurance.
How much is flood insurance in Alton?
FEMA’s Community Rating System list shows no discount for Alton’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 Alton?
By FEMA money that reached Alton, Severe Storms and Flooding (2007): 5 households applied for aid, $5K approved, and $655K to the Town of Alton for repairs.
Is Alton at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (76%), and Alton’s rate for it is higher than 66% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Alton.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Alton’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.