Natural hazards · Dorchester

Dorchester, NH natural hazards

Most of the natural-hazard damage FEMA expects in Dorchester comes from inland flooding, and overall the risk is very high for a U.S. community. Flood insurance has paid 3 claims here since 2000. 10 federal disasters brought FEMA money into town.

FEMA National Risk Index, December 2025 · OpenFEMA claims, aid & declarations

Expected damage

How exposed is Dorchester?

Very high

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Dorchester to be higher than in 81% of U.S. communities, mostly from inland flooding.

Inland flooding85%Everything else16%

By hazard

What Dorchester faces

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

Inland flooding

85% of expected damage

Well above average · higher than 94% of U.S. places

Recorded about 4 times a year in the area

Lower here

HurricanesTornadoesHailIce stormsWinter weatherCold wavesHeat wavesWildfireEarthquakesLandslidesStrong windLightningAvalanches

Not a risk here

Coastal floodingDroughtTsunamisVolcanic activity

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

Flood insurance claims

Does Dorchester flood?

Every paid claim on a federal flood insurance policy in Dorchester, from FEMA’s records.

3paid claims since 2000

$71Kpaid to owners

0homes flooded more than once

20002026

Biggest named events

Hurricane Irene: 1 claim, $2K

of homes in flood zones
are insured

of all homes
are insured

No community discount. Dorchester isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.

Insurance rates: Grafton County.

Disasters that hit Dorchester

10 federal disasters brought FEMA money here

Disasters the President declared that paid out in Dorchester itself: aid to households, or repair grants to the Town of Dorchester.

Brought FEMA money into DorchesterDeclared for Grafton County only

2023

Severe Storms and Flooding

$8K to the Town of Dorchester for repairs

2022

Severe Storm and Flooding

$10K to the Town of Dorchester for repairs

2019

Severe Storm and Flooding

$39K to the Town of Dorchester for repairs

2017

Severe Storms and Flooding

$260K to the Town of Dorchester for repairs

2011

Tropical Storm Irene

$126K to the Town of Dorchester for repairs

2011

Severe Storms and Flooding

$24K to the Town of Dorchester for repairs

2010

Severe Winter Storm

$21K to the Town of Dorchester for repairs

2008

Severe Storms and Flooding

$14K to the Town of Dorchester for repairs

2001

Snow

$5K to the Town of Dorchester for repairs

1999

Tropical Storm Floyd

$2K to the Town of Dorchester for repairs

Grafton County has had 32 natural disasters declared since 1953, most often severe storms and floods.

Around Dorchester

Dorchester and the towns around it

Very lowLowModerateHighVery high

Wentworthmostly inland floodingVery high

Dorchestermostly inland floodingVery high

Grotonmostly inland floodingVery high

Lymemostly inland floodingVery high

Orangemostly inland floodingVery high

Canaanmostly inland floodingVery high

Rumneymostly inland floodingHigh

About these numbers

How to read this page

An average, not a forecastFEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.

Compared by rate“Higher than N%” compares yearly damage as a share of what’s here, so a big city isn’t rated riskier just for having more buildings. Dorchester covers 1 census tract, combined by population.

Money that reached townFlood claims are matched to Dorchester’s own flood-insurance community (here, the census tracts inside it); household aid to the registrant’s city; repair grants to the Town of Dorchester. FEMA’s model follows property values, so a place that recently lost many homes can rate lower than it feels.

FEMA’s expected losses across Dorchester total about $1.8M a year, counting buildings, people and crops.

Sources: FEMA National Risk Index (December 2025); 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. Census tracts: U.S. Census Bureau.