Pennsylvania Environment & Hazard Risk
5 counties rated high or very high risk. 49,838 storm events since 1996, #14 among states.
- Expected yearly loss
- $4.07B
- $313 per person
- Storm events since 1996
- 49,838
- Most often thunderstorm wind
- Flood insurance policies
- 31,965
- $1.43B in claims paid
- Superfund sites
- 127
- 1,044 toxic release facilities
Risk by county
FEMA National Risk Index rating, highest risk first
| County | Overall risk | Top hazard | Flood policies | Flood claims paid |
|---|---|---|---|---|
| Philadelphia County | Very High | Heat wave | 1,383 | $47.61M |
| Allegheny County | High | Cold wave | 1,851 | $81.56M |
| Montgomery County | High | Winter weather | 2,284 | $185M |
| Lancaster County | High | Winter weather | 678 | $32.8M |
| Bucks County | High | Winter weather | 2,658 | $150M |
| Lehigh County | Moderate | Cold wave | 423 | $12.44M |
| Delaware County | Moderate | Winter weather | 1,153 | $57.24M |
| Berks County | Moderate | Winter weather | 684 | $23.61M |
| Chester County | Moderate | Drought | 1,015 | $37.56M |
| Luzerne County | Moderate | Winter weather | 3,881 | $93.95M |
| Dauphin County | Moderate | Winter weather | 1,130 | $86.09M |
| York County | Moderate | Winter weather | 674 | $20.71M |
| Northampton County | Moderate | Winter weather | 594 | $48.39M |
| Lackawanna County | Moderate | Winter weather | 878 | $20.54M |
| Westmoreland County | Moderate | Lightning | 752 | $21.57M |
| Cumberland County | Moderate | Winter weather | 555 | $16.91M |
| Schuylkill County | Moderate | Winter weather | 596 | $26.28M |
| Monroe County | Moderate | Lightning | 356 | $14.76M |
| Erie County | Moderate | Lightning | 290 | $5.97M |
| Washington County | Moderate | Landslide | 468 | $21.07M |
| Fayette County | Moderate | Landslide | 208 | $10.09M |
| Lebanon County | Low | Winter weather | 221 | $15.94M |
| Lycoming County | Low | Winter weather | 661 | $58.33M |
| Butler County | Low | Lightning | 326 | $15.41M |
| Northumberland County | Low | Winter weather | 365 | $24.25M |
| Mercer County | Low | Lightning | 62 | $880K |
| Blair County | Low | Winter weather | 500 | $8.53M |
| Cambria County | Low | Lightning | 357 | $3.24M |
| Franklin County | Low | Hurricane | 213 | $1.08M |
| Crawford County | Low | Winter weather | 251 | $1.67M |
| Beaver County | Low | Landslide | 205 | $13.69M |
| Bradford County | Low | Lightning | 458 | $24.79M |
| Armstrong County | Low | Landslide | 212 | $6.19M |
| Mifflin County | Low | Winter weather | 160 | $3.85M |
| Bedford County | Low | Landslide | 235 | $13.35M |
| Centre County | Low | Winter weather | 266 | $2.98M |
| Adams County | Low | Drought | 266 | $6.7M |
| Clearfield County | Low | Winter weather | 195 | $5.9M |
| Lawrence County | Low | Lightning | 126 | $1.96M |
| Pike County | Low | Hurricane | 172 | $2.96M |
| Warren County | Low | Strong wind | 154 | $1.09M |
| Somerset County | Low | Landslide | 257 | $2.59M |
| Indiana County | Low | Landslide | 171 | $2.35M |
| Columbia County | Low | Winter weather | 490 | $63.17M |
| Tioga County | Low | Landslide | 282 | $3.53M |
| Carbon County | Low | Lightning | 152 | $451K |
| Jefferson County | Low | Lightning | 117 | $7.73M |
| Wayne County | Low | Hurricane | 152 | $4.72M |
| Venango County | Low | Lightning | 92 | $5.9M |
| Union County | Low | Strong wind | 231 | $11.75M |
| Greene County | Low | Landslide | 87 | $3.51M |
| Snyder County | Low | Winter weather | 194 | $12.45M |
| McKean County | Low | Winter weather | 181 | $1M |
| Susquehanna County | Low | Landslide | 176 | $13.36M |
| Perry County | Low | Landslide | 180 | $7.44M |
| Clinton County | Low | Strong wind | 336 | $8.2M |
| Huntingdon County | Low | Strong wind | 234 | $8.83M |
| Elk County | Low | Lightning | 82 | $8.29M |
| Wyoming County | Low | Landslide | 198 | $28.57M |
| Juniata County | Very Low | Landslide | 68 | $1.12M |
| Clarion County | Very Low | Lightning | 37 | $2.93M |
| Potter County | Very Low | Landslide | 122 | $1.12M |
| Forest County | Very Low | Lightning | 18 | $194K |
| Montour County | Very Low | Hurricane | 62 | $3.19M |
| Cameron County | Very Low | Landslide | 57 | $532K |
| Sullivan County | Very Low | Landslide | 58 | $3.92M |
| Fulton County | Very Low | Landslide | 15 | $363K |
Costliest hazards
Expected annual loss in Pennsylvania, all counties combined
- Heat wave$365M/yr · 3 counties high
- Cold wave$256M/yr · 11 counties high
- Hurricane$170M/yr · 2 counties high
- Tornado$153M/yr · 6 counties high
- Earthquake$148M/yr · 1 county high
- Strong wind$97.18M/yr · 20 counties high
- Lightning$55.18M/yr · 31 counties high
- Winter weather$33.22M/yr · 25 counties high
- Drought$20.86M/yr · 2 counties high
- Hail$14.91M/yr · 1 county high
Storm events by type
Since 1996: 815 deaths, $4.24B in property and crop damage
- Thunderstorm Wind20,142 · 41 deaths
- Flash Flood4,935 · 77 deaths
- Hail4,647
- Winter Weather3,470 · 56 deaths
- Heavy Snow2,452 · 15 deaths
- Winter Storm2,447 · 44 deaths
- Flood2,207 · 33 deaths
- High Wind1,628 · 26 deaths
- Strong Wind1,259 · 14 deaths
- Drought812
- Heat711 · 318 deaths
- Tornado614 · 7 deaths
Events per year
Most damaging storms
Since 2017, ranked by deaths, injuries and damage
- Winter Weather03/28/2022
Schuylkill
6 deaths, 24 injured
What happened
SNOW SQUALL. A snow squall passed over I-81 in Schuylkill County shortly after 10:30am (EDT) on March 28, 2022, causing an 80 vehicle pileup at mile marker 116 on the northbound lanes that resulted in 6 fatalities, an additional 24 injuries, and closed the northbound lanes between mile markers 107 and 119 for more than 24 hours. State Route 901 was also closed.
- Flash Flood07/15/2023
Buckmanville, Bucks County
7 deaths
What happened
Catastrophic flash flooding occurred in Upper Makefield Township, resulting in the loss of seven lives. A reliable rain gauge located within the township indicated that 4.64 inches of rain fell during the event which lasted less than 2 hours. Widespread roadway flooding occurred with many roads becoming impassable. Numerous water rescues took place in the township. The worst of the flooding occurred along Hough's Creek. The creek rose rapidly and the rushing water carried away many vehicles, most along Taylorsville Road which parallels the Delaware Canal. Eleven vehicles were reported to have been swept into the creek. Eight individual were rescued from their vehicle and two from the creek. Unfortunately, seven people perished either while trapped in their vehicle or while attempting to escape the flood waters.||The Taylorsville Road Bridge over Hough's Creek was structurally compromised. PA Route 532 between Stonebridge Crossing Road and Wrightstown Road was damaged severely by the raging flood waters from Hough's Creek.
- Flash Flood09/02/2021
Wayne Jct, Philadelphia County
$60M damage
What happened
Widespread flash flooding occurred in Philadelphia with many roadways closed. Most of the waterways in the city overflowed their banks, including the Schuylkill River, Cobbs Creek, Wissahickon Creek, Frankford Creek and Pennypack Creek. Many buildings were flooded, especially in the Manayunk section of the city.
- Flash Flood09/01/2021
Nottingham, Chester County
1 death, $41M damage
What happened
Widespread flash flooding occurred in Chester County with many road closures and vehicles stranded. There was a flood related fatality in Downingtown. Numerous waterways in the county flooded, including the Schuylkill River, the West Branch of the Brandywine Creek, the East Branch of the Brandywine Creek, White Clay Creek, Red Clay Creek, French Creek and Valley Creek. There were many reports of water entering buildings and homes.
- Flash Flood09/01/2021
King of Prussia, Montgomery County
2 deaths, $21M damage
What happened
Widespread flash flooding occurred in Montgomery County with many road closures and vehicles stranded. Numerous water rescues took place. There were two flood related fatalities, one in Skippack and one in Bridgeport. Many buildings and homes were flooded. Most waterways in the county overflowed their banks, including the Schuylkill River, Perkiomen Creek and Wissahickon Creek.
- Flash Flood09/02/2021
Byberry, Philadelphia County
$40M damage
What happened
Widespread flash flooding occurred in Philadelphia with many roadways closed. Most of the waterways in the city overflowed their banks, including the Schuylkill River, Cobbs Creek, Wissahickon Creek, Frankford Creek and Pennypack Creek. Many buildings were flooded, especially in the Manayunk section of the city.
Hurricanes and tropical storms
Storms whose track crossed the state, newest first
- Hurricane Debby (2024)08/02/2024 · Landfall: FL, SC · 979 mbCategory 181 mph peak
- Hurricane Ida (2021)08/26/2021 · Landfall: LA · 929 mbCategory 4150 mph peak
- Tropical Storm Fred (2021)08/10/2021 · Landfall: FL · 991 mbTropical storm63 mph peak
- Hurricane Isaias (2020)07/28/2020 · Landfall: NC · 986 mbCategory 192 mph peak
- Hurricane Florence (2018)08/30/2018 · Landfall: NC · 937 mbCategory 4150 mph peak
- Hurricane Nate (2017)10/03/2017 · Landfall: LA, MS · 981 mbCategory 192 mph peak
- Hurricane Sandy (2012)10/22/2012 · Landfall: NJ · 940 mbCategory 3115 mph peak
- Hurricane Ernesto (2006)08/25/2006 · Landfall: FL, NC · 985 mbCategory 175 mph peak
- Hurricane Frances (2004)08/25/2004 · Landfall: FL · 935 mbCategory 4144 mph peak
- Hurricane Isabel (2003)09/06/2003 · Landfall: NC · 915 mbCategory 5167 mph peak
Flood insurance
National Flood Insurance Program policies and claims
31,965 homes in Pennsylvania have flood insurance, about 0.7% of residential buildings. In high-risk flood zones, 21,245 of 92,246 homes (23%) are insured.
- Tropical Storm Lee$302M · 7,848 claims
- Tropical Storm Ivan$182M · 8,116 claims
- Flooding$133M · 12,137 claims
- Hurricane Ida$108M · 1,802 claims
- Hurricane Floyd$54.28M · 1,754 claims
- Hurricane Irene$39.81M · 1,474 claims
Drinking water
1,849 community water systems serve about 11,466,690 people
Since 2021, 500 systems reported 1,271 health-based violations. 238 systems had a violation of any kind still open at last report. These had the most:
- Pithole Water AssociationServes 87 · Groundwater · Private33 health violations+103 monitoring or reporting
- Parker Area Water AuthServes 900 · Surface water · Local government27 health violations+6 monitoring or reporting
- Pinecrest Village MhpServes 195 · Groundwater (surface influenced) · Private22 health violations+382 monitoring or reporting
- Icmsa RossiterServes 500 · Surface water · Local government21 health violations+13 monitoring or reporting
- Clarendon Acres Water CoServes 280 · Groundwater · Private18 health violations+84 monitoring or reporting
- Woodhaven Mobile Home ParkServes 350 · Surface water · Private17 health violations+267 monitoring or reporting
- Blawnox Boro Water DeptServes 2,200 · Purchased surface water · Local government15 health violations+19 monitoring or reporting
- Polk CenterServes 1,058 · Surface water · State15 health violations+96 monitoring or reporting
Select a county above to see every system that serves it.
Climate in the largest cities
1991-2020 normals from the nearest NOAA weather station
| City | July high | Jan low | Rain | Snow |
|---|---|---|---|---|
| Philadelphia | 89°F | 28°F | 50.7 in | 16.1 in |
| Pittsburgh | 83°F | 22°F | 41.3 in | - |
| Allentown | 86°F | 22°F | 47.4 in | 33.1 in |
| Reading | 87°F | 23°F | 45.2 in | - |
| Erie | 81°F | 21°F | 43.0 in | 104.3 in |
| Scranton | 85°F | 20°F | 38.7 in | 45.1 in |
| Lancaster | 87°F | 22°F | 44.1 in | 21.4 in |
| Levittown | 86°F | 22°F | 50.7 in | 19.9 in |
Pollution sites
127 Superfund sites and 1,044 toxic release facilities
Superfund sites
- Avco Lycoming (Williamsport Division)Final NPL Site, Williamsport
- Baghurst DriveFinal NPL Site, Harleysville
- Bally Ground Water ContaminationFinal NPL Site, Bally
- Bell LandfillFinal NPL Site, Terry Township
- Bendix Flight Systems DivisionFinal NPL Site, South Montrose
- Berks Sand PitFinal NPL Site, Longswamp Township
- Blosenski LandfillFinal NPL Site, West Caln Township
- Boarhead FarmsFinal NPL Site, Bridgeton Township
Largest toxic releases
- Uss Mon Valley Works - Edgar Thomson Plant4.2 million lbs, Braddock
- Uss-Clairton Plant3.2 million lbs, Clairton
- Carpenter Technology Corp2.5 million lbs, Reading
- Cleveland-Cliffs Steel Corp /Butler Works2.3 million lbs, Butler
- Conemaugh Generating Station1.4 million lbs, New Florence
- Max Environmental -- Yukon Facility1.1 million lbs, Yukon
- Keystone Power Plant1.1 million lbs, Shelocta
- Ati Flat Rolled Products Holdings LLC1.1 million lbs, Vandergrift
Facilities in Pennsylvania reported 42.3 million lbs of toxic releases in 2024, 10.8 million lbs of it into the air.
Frequently asked questions
- What is the biggest natural hazard in Pennsylvania?
- By expected annual loss, heat wave costs the most in Pennsylvania ($365M a year), according to FEMA's National Risk Index.
- How many storms hit Pennsylvania each year?
- NOAA recorded 49,838 storm events in Pennsylvania since 1996, about 1,608 a year. The most common type is thunderstorm wind.
- How many homes in Pennsylvania have flood insurance?
- 31,965 residential flood insurance policies are in force in Pennsylvania. Since 1978 the National Flood Insurance Program has paid $1.43B on 75,803 claims here.
- How many Superfund sites are in Pennsylvania?
- Pennsylvania has 127 Superfund sites on or deleted from EPA's National Priorities List.
Source: FEMA, NOAA, EPA · Last updated 08/01/2026 · Storm counts include events in forecast zones that touch each county. This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.