Chester County, Pennsylvania: hazard risk
FEMA rates Chester County's overall risk Relatively Moderate (score 91.9 of 100, higher than 91% of rated U.S. counties); 6 of its 15 hazards are rated Relatively High or Very High, led by winter weather, drought, strong wind. Its storm record holds 2,132 events since 1950.
FEMA's rating for each hazard
These are FEMA's county-wide model ratings and this county's storm record. They are not an assessment of any property, address or building, and not insurance advice: a property's risk depends on its own elevation, construction and location.
FEMA gives each hazard its own rating, and a rating does not follow the score from one hazard to the next: a hazard with a higher score can carry a lower rating than another. The table sorts by FEMA's rating, then by score (0 to 100, the county against every other county for that hazard).
| Hazard | Risk rating | Score | Expected annual loss |
|---|---|---|---|
| Winter Weather | Very High | 98.4 | $2.3M |
| Drought | Relatively High | 98.6 | $10M |
| Strong Wind | Relatively High | 94.6 | $4.6M |
| Riverine Flooding | Relatively High | 94.3 | $106M |
| Lightning | Relatively High | 91.4 | $2.1M |
| Ice Storm | Relatively High | 85.7 | $993K |
| Heat Wave | Relatively Moderate | 95.6 | $11M |
| Earthquake | Relatively Moderate | 90.2 | $8.5M |
| Hurricane | Relatively Moderate | 88.7 | $9.6M |
| Tornado | Relatively Moderate | 88.0 | $9.8M |
| Cold Wave | Relatively Moderate | 84.2 | $7.5M |
| Landslide | Relatively Low | 77.8 | $20K |
| Hail | Relatively Low | 61.2 | $618K |
| Wildfire | Very Low | 30.7 | $23K |
| Coastal Flooding | No Rating | 0.0 | $0 |
Source: FEMA National Risk Index, December 2025 release. A model of future loss, not a count of past events. FEMA's National Risk Index map.
What the record holds
| Hazard | Records | Deaths | Damage | Rank in state | Rank in U.S. |
|---|---|---|---|---|---|
| Severe thunderstorm wind | 782 | 3 | $12M | 13th of 67 | 317th of 3,080 |
| Winter storms | 382 | 0 | $13M | 10th of 67 | 216th of 3,077 |
| Floods | 316 | 3 | $71M | 8th of 67 | 129th of 3,080 |
| High wind and dust storms | 146 | 1 | $18M | 9th of 67 | 165th of 3,080 |
| Heat | 112 | 11 | – | 7th of 67 | 205th of 3,076 |
| Hail | 102 | 0 | $160 | 22nd of 67 | 1803rd of 3,080 |
| Heavy rain | 50 | 1 | – | 8th of 67 | 148th of 3,080 |
| Lightning | 46 | 3 | $3.8M | 8th of 67 | 125th of 3,080 |
| Drought | 44 | 0 | – | 9th of 67 | 789th of 3,063 |
| Extreme cold | 42 | 0 | $22M | 11th of 67 | 627th of 3,076 |
| Tornadoes | 29 | 2 | $34M | 9th of 67 | 1316th of 3,080 |
| Hurricanes and tropical storms | 4 | 0 | $1.1M | 8th of 67 | 764th of 1,849 |
| Wildfires | 3 | 0 | – | 11th of 67 | 756th of 2,972 |
Source: NOAA NCEI Storm Events Database, 1950 to 2026-06-30; damage in 2025 dollars. Search the record at NCEI.
The full Chester County record: every hazard by year and month, the deadliest events and FEMA's declarations.