Adams County, Pennsylvania: Natural Disaster Risk and History
Adams County, Pennsylvania has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 67.5 out of 100, higher than about 67% of US counties, with drought, hurricanes and inland (river and flash) flooding scoring highest of its 18 hazards and $27 million a year in expected losses.
OpenFEMA lists 18 federal disaster declarations that included Adams County since 1972, not counting 2 for COVID-19; the latest is DR-4267-PA (Severe Winter Storm and Snowstorm, declared 23 March 2016). NOAA's Storm Prediction Center recorded 16 tornadoes touching Adams County from 1950 to 2025.
Live weather alerts for Pennsylvania All official warnings Latest FEMA declarations
Population 103,797 Buildings worth $23 billion Area 527 sq mi Risk rank in Pennsylvania 37 of 67 FIPS 42001
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Drought | Relatively Moderate | 87.6 | $1.4 million | about 3.3 a year | 133 |
| Hurricane | Relatively Moderate | 84.1 | $3.4 million | about once every 13 years | 28 |
| Inland flooding | Relatively Moderate | 76.2 | $17 million | about 1.6 a year | 46 |
| Strong wind | Relatively Moderate | 72.7 | $1.1 million | about 6.6 a year | 249 |
| Earthquake | Relatively Low | 72.6 | $976,761 | about once every 893 years | — |
| Winter weather | Relatively Moderate | 71.5 | $141,005 | about 12 a year | 225 |
| Heat wave | Relatively Low | 68.6 | $881,935 | about 4.8 a year | 70 |
| Lightning | Relatively Low | 56.5 | $300,792 | about 37 a year | 155,598 strikes |
| Tornado | Relatively Low | 46.2 | $1.1 million | about once every 3.1 years | 15 |
| Ice storm | Relatively Low | 46.2 | $73,702 | about once every 1.1 years | 62 |
| Wildfire | Very Low | 44.2 | $34,061 | rarer than once in 1,000 years | — |
| Landslide | Very Low | 39.4 | $643 | about once every 4.5 years | — |
| Hail | Very Low | 32.7 | $136,979 | about 3.1 a year | 117 |
| Cold wave | Relatively Low | 26.5 | $362,702 | about 1.2 a year | 22 |
| Avalanche | Not Applicable | — | — | — | — |
| Coastal flooding | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| 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 18
Most common: Flood 7, Snowstorm 4, Severe Storm 4, Hurricane 3.
| Decade | Declarations | Incident types |
|---|---|---|
| 1970s | 3 | Flood ×3 |
| 1990s | 5 | Flood ×2, Snowstorm ×2, Severe Storm |
| 2000s | 5 | Severe Storm ×3, Hurricane ×2 |
| 2010s | 5 | Snowstorm ×2, Flood ×2, Hurricane |
The last 10
Widest declarations that included Adams County
- Hurricane Sandy (2012, EM-3356-PA): 67 Pennsylvania counties designated.
- Hurricane Katrina (2005, EM-3235-PA): 67 Pennsylvania counties designated.
- Tropical Depression Ivan (2004, DR-1557-PA): 67 Pennsylvania counties designated.
Named storms in its declarations: Hurricane Sandy (2012), Tropical Storm Lee (2011), Hurricane Katrina (2005), Tropical Depression Ivan (2004), Tropical Depression Frances (2004), Tropical Storm Agnes (1972).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Pennsylvania also had 5 statewide declarations with no county list.
Tornado record since 1950 16
| Tornadoes touching the county | 16 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | August (5) |
| Deadliest | — |
| Longest path | 25 Apr 1954, F2, 13.3 mi path |
| Most recent | 18 Aug 2021, EF0, 0.6 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 2 | 10 | 3 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 2 | 0 | 2 | 2 | 6 | 3 | 0 | 1 |
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 Adams County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Adams County (this page) | — | Relatively Low | 67.5 | Drought |
| Cumberland County | 33 km | Relatively Moderate | 86.2 | Winter weather |
| Carroll County, MD | 38 km | Relatively Low | 59.5 | Strong wind |
| York County | 42 km | Relatively Moderate | 90.4 | Winter weather |
| Franklin County | 43 km | Relatively Low | 76.4 | Hurricane |
| Frederick County, MD | 47 km | Relatively Low | 74.2 | Winter weather |
Nearest by distance between county centres. Every county in Pennsylvania, ranked.
Vulnerability and resilience
| Social vulnerability | Relatively Low 36.2 |
|---|---|
| Community resilience | Relatively High 66.6 |
| Community risk factor | 1.02 |
| Expected annual loss, all hazards | $27 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 Adams County's main hazards
- Right now: National Weather Service alerts for Pennsylvania · all official warnings on Global Incident Tracker.
- Drought: Drought monitor for Pennsylvania
- Hurricane: Is there a hurricane now? · Cyclone preparation
- Inland flooding: Flood safety: why shallow water kills · Floods recorded
- 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 Adams County
What natural disasters is Adams County, Pennsylvania most at risk from?
Adams County, Pennsylvania has a Relatively Low natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 67.5 out of 100, higher than about 67% of US counties, with drought, hurricanes and inland (river and flash) flooding scoring highest of its 18 hazards and $27 million a year in expected losses.
How many federal disaster declarations has Adams County had?
OpenFEMA lists 18 federal disaster declarations that included Adams County since 1972, not counting 2 for COVID-19; the latest is DR-4267-PA (Severe Winter Storm and Snowstorm, declared 23 March 2016). Another 5 Pennsylvania declarations were made statewide without a county list.
How many tornadoes have hit Adams County?
NOAA's Storm Prediction Center recorded 16 tornadoes touching Adams County from 1950 to 2025.
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.