George Thorndike House · Photo: Magicpiano · CC BY-SA 4.0South Thomaston’s building-damage rate from coastal flooding is in the top 1% of U.S. census tracts
On FEMA’s National Risk Index, South Thomaston gets a B for hazard risk: lower expected damage per building than 65% of U.S. towns. Most of that expected damage is hurricanes (39%), then river and rain flooding (25%). Flood insurance has paid 4 claims here since 2010.
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 South Thomaston’s natural hazards
From FEMA’s model and FEMA’s records, below.
What South Thomaston faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
Hurricanes
River and rain flooding
Coastal flooding
Ice storms
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 South Thomaston’s grade
Hurricanes are 39% of the building damage FEMA expects in South Thomaston, and South Thomaston’s rate of hurricanes damage is higher than 88% of U.S. census tracts. Coastal flooding adds 23%, at a rate in the top 1% of U.S. census tracts.
B lower expected damage per building than 65% of U.S. towns (21,298).
All of South Thomaston’s residents live in one census tract; the figures are that tract’s.
In dollars, FEMA expects about $411K a year in losses across South Thomaston: $351K to buildings, the rest to people and crops.
Does South Thomaston flood? Rarely: 4 flood claims since 2010
Every paid claim on a federal flood insurance policy in South Thomaston, from FEMA’s records: 4.9 per 1,000 homes, more than 60% of the 13,809 U.S. towns with a flood insurance record.
South Thomaston isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Knox County.2 federal disasters brought FEMA money to South Thomaston
Disasters that paid out in South Thomaston itself (aid to households or repair grants to the Town of South Thomaston), newest first, with that year’s flood claims.
- 2024Severe Storms and Flooding11 households applied for aid$10K aid approved3 flood claims paid that year
- 2007Severe Storms and Inland and Coastal Flooding6 households applied for aid$251 aid approved
Knox County has had 25 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 South Thomaston after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the South Thomaston archive →South Thomaston and its neighbors
South Thomaston is 5th of the 6 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 |
|---|---|---|---|
| Rockland | Aless damage than 86% | hurricanes | 7 |
| Cushing | B+less damage than 66% | hurricanes | — |
| Thomaston | B+less damage than 65% | hurricanes | 6 |
| Owls Head | Bless damage than 65% | hurricanes | 11 |
| South Thomaston | Bless damage than 65% | hurricanes | 4 |
| St. George | B−more damage than 52% | coastal flooding | 4 |
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 South Thomaston faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- 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.
- 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.
- Ice brings down trees and lines: plan for days without power.
- Run a generator outside, far from doors and windows.
- Keep sand or salt by the door.
- 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 South Thomaston
Is South Thomaston at risk for natural disasters?
On FEMA’s National Risk Index, South Thomaston has lower expected damage per building than 65% of U.S. towns: B for hazard risk. Most of the expected damage is hurricanes (39%) and river and rain flooding (25%). 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 South Thomaston flood?
Flood insurance has paid 4 claims in South Thomaston since 2010, $109K in all, or 4.9 per 1,000 homes, more than 60% of U.S. towns with a flood insurance record.
Is South Thomaston 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 Knox County, 30% of homes in mapped flood zones carry federal flood insurance, and 1.5% of all homes do.
How much is flood insurance in South Thomaston?
FEMA’s Community Rating System list shows no discount for South Thomaston’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 South Thomaston?
By FEMA money that reached South Thomaston, Severe Storms and Flooding (2024): 11 households applied for aid, $10K approved.
Is South Thomaston at risk from hurricanes?
It is the largest share of the building damage FEMA expects here (39%), and South Thomaston’s rate for it is higher than 88% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in South Thomaston.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where South Thomaston’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.