Norfolk County, Massachusetts: Natural Disaster Risk and History
Norfolk County, Massachusetts has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 92.0 out of 100, higher than about 92% of US counties, with inland (river and flash) flooding, hurricanes and earthquakes scoring highest of its 18 hazards and $147 million a year in expected losses.
OpenFEMA lists 36 federal disaster declarations that included Norfolk County since 1972, not counting 2 for COVID-19; the latest is EM-3599-MA (Hurricane Lee, declared 15 September 2023). NOAA's Storm Prediction Center recorded 15 tornadoes touching Norfolk County from 1950 to 2025.
Live weather alerts for Massachusetts All official warnings Latest FEMA declarations
Population 725,648 Buildings worth $167 billion Area 449 sq mi Risk rank in Massachusetts 6 of 14 FIPS 25021
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Inland flooding | Relatively High | 95.5 | $103 million | about 2.9 a year | 80 |
| Hurricane | Relatively Moderate | 92.2 | $16 million | about once every 5.6 years | 54 |
| Earthquake | Relatively Moderate | 91.5 | $8.9 million | about once every 602 years | — |
| Ice storm | Relatively High | 89.7 | $1.2 million | about 1.8 a year | 115 |
| Heat wave | Relatively Moderate | 89.6 | $3.9 million | about 6.1 a year | 94 |
| Lightning | Relatively High | 85.5 | $1.3 million | about 21 a year | 212,812 strikes |
| Coastal flooding | Relatively High | 85.2 | $5.1 million | about 7.9 a year | — |
| Cold wave | Relatively Moderate | 73.9 | $3.3 million | about 1.3 a year | 23 |
| Landslide | Relatively Low | 72.1 | $9,376 | about once every 4.3 years | — |
| Tornado | Relatively Moderate | 69.0 | $3.2 million | about once every 12 years | 13 |
| Strong wind | Relatively Moderate | 66.3 | $1.1 million | about once every 1.1 years | 35 |
| Wildfire | Very Low | 49.8 | $60,867 | rarer than once in 1,000 years | — |
| Winter weather | Relatively Low | 49.2 | $81,269 | about 13 a year | 228 |
| Drought | Relatively Low | 41.4 | $97,921 | about 5.8 a year | 238 |
| Hail | Very Low | 10.2 | $42,613 | about 1.8 a year | 75 |
| Avalanche | Not Applicable | — | — | — | — |
| Tsunami | Insufficient Data | — | — | — | — |
| Volcanic activity | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 36
Most common: Snowstorm 9, Hurricane 8, Severe Storm 7, Flood 7.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 3 | Flood ×2, Fishing Losses |
| 1980s | 2 | Flood, Hurricane |
| 1990s | 8 | Flood ×3, Snowstorm ×2, Coastal Storm ×2, Hurricane |
| 2000s | 8 | Snowstorm ×4, Severe Storm ×2, Hurricane, Flood |
| 2010s | 13 | Severe Storm ×5, Hurricane ×4, Snowstorm ×2, Terrorist, Other |
| 2020s | 2 | Hurricane, Snowstorm |
The last 10
Widest declarations that included Norfolk County
- Hurricane Lee (2023, EM-3599-MA): 14 Massachusetts counties designated.
- Severe Winter Storm, Snowstorm, and Flooding (2013, DR-4110-MA): 14 Massachusetts counties designated.
- Hurricane Sandy (2012, EM-3350-MA): 14 Massachusetts counties designated.
Named storms in its declarations: Hurricane Lee (2023), Hurricane Sandy (2012), Tropical Storm Irene (2011), Hurricane Irene (2011), Hurricane Earl (2010), Hurricane Katrina (2005), Hurricane Bob (1991), Hurricane Gloria (1985).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Massachusetts also had 6 statewide declarations with no county list.
Tornado record since 1950 15
| Tornadoes touching the county | 15 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | August (4) |
| Deadliest | 9 Aug 1972, F1, 4.9 mi path, 1 killed, 6 injured |
| Longest path | 9 Jun 1953, F3, 28 mi path, 0 killed, 17 injured |
| Most recent | 18 Aug 2023, EF0, 0.1 mi path |
| Deaths / injuries on those paths | 1 / 23 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 8 | 5 | 1 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 2 | 0 | 2 | 1 | 2 | 2 | 2 | 4 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Norfolk County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Norfolk County (this page) | — | Relatively Moderate | 92.0 | Inland flooding |
| Suffolk County | 22 km | Relatively Moderate | 93.5 | Lightning |
| Middlesex County | 39 km | Relatively High | 96.9 | Ice storm |
| Plymouth County | 40 km | Relatively Moderate | 90.4 | Coastal flooding |
| Bristol County | 41 km | Relatively Moderate | 89.9 | Inland flooding |
| Providence County, RI | 44 km | Relatively Moderate | 93.7 | Heat wave |
Nearest by distance between county centres. Every county in Massachusetts, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 12.8 |
|---|---|
| Community resilience | Very High 93.0 |
| Community risk factor | 0.80 |
| Expected annual loss, all hazards | $147 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Norfolk County's main hazards
- Right now: National Weather Service alerts for Massachusetts · all official warnings on Global Incident Tracker.
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- Hurricane: Is there a hurricane now? · Cyclone preparation
- Earthquake: Earthquakes today · Earthquake safety guide
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. This product uses the Federal Emergency Management Agency’s National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Norfolk County
What natural disasters is Norfolk County, Massachusetts most at risk from?
Norfolk County, Massachusetts has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 92.0 out of 100, higher than about 92% of US counties, with inland (river and flash) flooding, hurricanes and earthquakes scoring highest of its 18 hazards and $147 million a year in expected losses.
How many federal disaster declarations has Norfolk County had?
OpenFEMA lists 36 federal disaster declarations that included Norfolk County since 1972, not counting 2 for COVID-19; the latest is EM-3599-MA (Hurricane Lee, declared 15 September 2023). Another 6 Massachusetts declarations were made statewide without a county list.
How many tornadoes have hit Norfolk County?
NOAA's Storm Prediction Center recorded 15 tornadoes touching Norfolk County from 1950 to 2025. The deadliest: 9 Aug 1972, F1, 4.9 mi path, 1 killed, 6 injured (deaths and injuries are for the whole path).
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.