602 flood insurance claims·$17.6M paid·5 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Nantucket County, Massachusetts. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Coastal flooding dominates the flood character of Nantucket County, driven primarily by coastal flood events, general floods, tropical storms, and storm surge. Recent severe weather includes an explosive winter storm in January 2022 that brought blizzard conditions, extreme snowfall, and hurricane-force wind gusts, as well as a rapidly deepening low pressure system in December 2022 that produced damaging southeast-to-south winds and minor to moderate coastal flooding. Heavy rainfall from slow-moving low pressure systems also produced flooding in May 2020.
National Flood Insurance Program records show varying impacts across different zones. Zone A accounts for the highest claim volume with 373 claims averaging $31,478 and an average recorded water depth of 5 inches. Zone X unshaded recorded 88 claims with an average payout of $50,705 and an average water depth of 24 inches. Zone X recorded 82 claims with an average payout of $61,394 and an average water depth of 4 inches. Zone V recorded 26 claims with an average payout of $46,585 and an average water depth of 6 inches. Zone X shaded recorded 24 claims with an average payout of $22,379 and an average water depth of 2 inches. Coastal properties and homeowners in high-risk zones, particularly Zones A and V, should pay the closest attention to these flood risks.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
22% of Nantucket County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
511 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 7 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 1991, with 162 claims and $5.4M paid, the year of Hurricane Bob and Coastal Storm.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
25 NOAA storm reports from Nantucket County describe what happened, in the words of the forecasters who covered it. Read the Massachusetts flood stories →
20 federal disaster declarations since 1972, 5 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Hurricane Lee | Sep 15, 2023 |
| Severe Winter Storm And Flooding | Mar 2, 2018 |
| Severe Winter Storm, Snowstorm, And Flooding | Jan 26, 2015 |
| Severe Winter Storm, Snowstorm, And Flooding | Feb 8, 2013 |
| Hurricane Sandy | Oct 27, 2012 |
| Hurricane Irene | Aug 26, 2011 |
| Hurricane Earl | Sep 1, 2010 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
45 since 1996: 8 river or area floods and 30 coastal floods or surges.
| Event | Date | Damage |
|---|---|---|
| Coastal Flood | Jan 29, 2022 | — |
| Coastal Flood | Dec 23, 2022 | $1,000 |
| Flood | May 23, 2020 | — |
| Coastal Flood | Apr 3, 2020 | — |
| Coastal Flood | Oct 11, 2019 | — |
| Coastal Flood | Sep 7, 2019 | — |
| Tropical Storm | Sep 6, 2019 | $200 |
| Coastal Flood | Jan 30, 2018 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Coastal Flood · Jan 29, 2022. Explosive cyclogenesis of a low pressure center off the Mid Atlantic coast brought a strong winter storm with blizzard conditions to all of southern New England Saturday and Saturday night. The storm tracked from east of the Carolinas to the 70w/40n benchmark bringing extreme snowfall rates of 2 to 4 inches per hour and winds gusting to hurricane force along the coast and 50 to 60 mph inland. The heaviest snow, ju…
Coastal Flood · Dec 23, 2022. Low pressure deepened rapidly as it tracked through the eastern Great Lakes.|The storm produced damaging southeast to south winds across much of southern New England and minor to moderate coastal flooding the east and south coasts. There were two rounds of strong wind gusts -- one in the morning and one in the late afternoon and evening. Two to 3.5 inches of rain fell across much of RI and interior MA.
Flood · May 23, 2020. Surface low pressure (and an upper level low) passed just south of New England. At the same time, a strong upper level short wave was passing to our north and a strong backdoor cold front was moving southward into northeastern Massachusetts. A mid-level deformation zone set up over southeastern MA, which allowed an area of heavy rain to persist for several hours over Martha's Vineyard and Nantucket, producing so…
Coastal Flood · Apr 3, 2020. A large and intense ocean storm east of New England caused a period of coastal flooding at the time of high tide in the early to mid morning and strong, locally damaging winds from the late morning to mid afternoon. Heavy rain also fell, with 1.50 to 2.75 inches of rain reported in eastern Massachusetts. The storm then moved south and passed north of Bermuda on March 4.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Nantucket County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.