Photo: Wwoods · CC BY-SA 3.0On FEMA’s figures, Cohasset faces less hazard damage per building than 69% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Cohasset gets a B+ for hazard risk: lower expected damage per building than 69% of U.S. towns, #176 of 283 in Massachusetts. Most of that expected damage is river and rain flooding (51%), then coastal flooding (32%). Flood insurance has paid 107 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 Cohasset’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Cohasset 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
Coastal 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 Cohasset’s grade
River and rain flooding is 51% of the building damage FEMA expects in Cohasset, and Cohasset’s rate of river and rain flooding damage is lower than 79% of U.S. census tracts. Coastal flooding adds 32%, at a rate in the top 1% of U.S. census tracts.
B+ #176 of 283 in Massachusetts; lower expected damage per building than 69% of U.S. towns (21,298).
Cohasset’s residents live in 2 census tracts; FEMA’s figures are combined by where they live.
The typical Massachusetts town has lower expected damage than 76% of U.S. towns; within the state, Cohasset has more expected damage per building than 62% of Massachusetts towns.
In dollars, FEMA expects about $2.8M a year in losses across Cohasset: $2.6M to buildings, the rest to people and crops.
Does Cohasset flood? Yes: 107 flood claims since 1978
Every paid claim on a federal flood insurance policy in Cohasset, from FEMA’s records: 33.0 per 1,000 homes, more than 89% of the 13,809 U.S. towns with a flood insurance record.
- The “Halloween” storm28 claims · $631K
- The December Storm - nor’easter6 claims · $69K
Cohasset isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Norfolk County.13 federal disasters brought FEMA money to Cohasset
Disasters that paid out in Cohasset itself (aid to households or repair grants to the Town of Cohasset), newest first, with that year’s flood claims.
- 2022Severe Winter Storm and Snowstorm$70K to the Town of Cohasset for repairs
- 2018Severe Winter Storm and Snowstorm$43K to the Town of Cohasset for repairs
- 2018Severe Winter Storm and Flooding$12K to the Town of Cohasset for repairs
- 2015Severe Winter Storm, Snowstorm, and Flooding$79K to the Town of Cohasset for repairs1 flood claim paid that year
- 2013Severe Winter Storm, Snowstorm, and Flooding$103K to the Town of Cohasset for repairs1 flood claim paid that year
- 2011Tropical Storm Irene$58K to the Town of Cohasset for repairs
Show all 13
- 2011Severe Winter Storm and Snowstorm$27K to the Town of Cohasset for repairs
- 2010Severe Storms and Flooding12 households applied for aid$24K aid approved3 flood claims paid that year
- 2005Record And/or Near Record Snow$54K to the Town of Cohasset for repairs1 flood claim paid that year
- 2004Flooding2 households applied for aid$3K aid approved1 flood claim paid that year
- 2003Snow$26K to the Town of Cohasset for repairs
- 2003Snow$34K to the Town of Cohasset for repairs
- 2001Snow$26K to the Town of Cohasset for repairs3 flood claims paid that year
Norfolk County has had 29 natural disasters declared by the President since 1953, most often hurricanes and tropical storms, then winter storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Cohasset after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Cohasset archive →Cohasset and its neighbors
Cohasset is 2nd 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 |
|---|---|---|---|
| Hingham | A−less damage than 83% | river and rain flooding | 100 |
| Cohasset | B+less damage than 69% | river and rain flooding | 107 |
| Scituate | B+less damage than 68% | river and rain flooding | 3,519 |
| Hull | Dmore damage than 92% | coastal flooding | 1,980 |
| North Scituate | — | a Census area inside a town; graded with the town | |
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 Cohasset 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.
- Know your evacuation zone and the way off the coast.
- Storm surge comes fast: leave when you’re told, not when the water arrives.
- Move cars to high ground before king tides and nor’easters.
- 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 Cohasset
Is Cohasset at risk for natural disasters?
On FEMA’s National Risk Index, Cohasset has lower expected damage per building than 69% of U.S. towns: B+ for hazard risk, #176 of 283 in Massachusetts. Most of the expected damage is river and rain flooding (51%) and coastal flooding (32%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Cohasset flood?
Flood insurance has paid 107 claims in Cohasset since 1978, $1.4M in all, or 33.0 per 1,000 homes, more than 89% of U.S. towns with a flood insurance record. 10 properties have flooded more than once. The most claims came from The "Halloween" Storm (28).
Is Cohasset 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 Norfolk County, 43% of homes in mapped flood zones carry federal flood insurance, and 1.5% of all homes do.
How much is flood insurance in Cohasset?
FEMA’s Community Rating System list shows no discount for Cohasset’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 Cohasset?
By FEMA money that reached Cohasset, Severe Winter Storm, Snowstorm, and Flooding (2013): $103K to the Town of Cohasset for repairs. By flood claims, The "Halloween" Storm: 28 paid, $631K.
Is Cohasset at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (51%), and Cohasset’s rate for it is lower than 79% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Cohasset.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Cohasset’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.