Delaware County, Oklahoma Natural Disaster Risk
FEMA National Risk Index assessment · OK
MediumComposite Risk Score
National percentile: 83th
Delaware County faces medium composite natural disaster risk (NRI Risk Index score 82.7, 83th national percentile), driven primarily by ice storm and heat wave exposure. Expected annual loss across all 18 hazard types is $30M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Delaware County carries a medium composite natural disaster risk, with a National Risk Index score of 82.7 out of 100 — placing it in the 83rd national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in ice storm (freezing rain that coats surfaces in heavy, damaging ice) at Very High risk — $2M in expected annual loss and about 1.62 events per year; heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $2M in expected annual loss and about 17.21 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Medium risk — $936K in expected annual loss and about 0.01 events per year. Across all hazards, FEMA estimates $30M in expected annual loss for a population of 40K.
Beyond physical exposure, Delaware County has a very high social vulnerability rating (how susceptible the population is to harm) and a very low community resilience rating (its capacity to prepare for and recover from disasters). That combination — a more vulnerable population with limited resilience — can amplify the human cost of any given event.
History supports the rating: Delaware County has received 33 federal disaster declarations since 1973, including 18 for severe storm events and 7 for severe ice storm events. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding (severe storm), declared in June 2024.
Among 77 Oklahoma counties, Delaware County ranks #9 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Ice Storm | Very High | 1.62 / yr | $2M |
| Heat Wave | Medium | 17.21 / yr | $2M |
| Wildfire | Medium | 0.01 / yr | $936K |
| Strong Wind | High | 6.72 / yr | $1M |
| Tornado | Medium | 0.80 / yr | $4M |
| Riverine Flood | Medium | 1.39 / yr | $17M |
| Winter Weather | Medium | 10.26 / yr | $131K |
| Landslide | Low | 0.59 / yr | $6K |
| Cold Wave | Medium | 1.74 / yr | $2M |
| Hail | Low | 8.19 / yr | $382K |
| Lightning | Medium | 56.25 / yr | $320K |
| Drought | Medium | 13.46 / yr | $228K |
| Earthquake | Low | 0.00 / yr | $282K |
| Hurricane | Very Low | 0.01 / yr | $27K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Delaware County has received 33 federal disaster declarations since 1973, most recently Severe Storms, Straight-Line Winds, Tornadoes, and Flooding in June 2024. Most frequent causes: Severe Storm (18), Severe Ice Storm (7), Flood (3).
| Declared | Type | Disaster |
|---|---|---|
| June 2024 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| July 2023 | Severe Storm | Severe Storms, Straight-Line Winds, and Tornadoes |
| February 2021 | Severe Ice Storm | Severe Winter Storms |
| February 2021 | Severe Ice Storm | Severe Winter Storm |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| June 2019 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| July 2017 | Tornado | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| May 2017 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| February 2016 | Severe Storm | Severe Winter Storms and Flooding |
Showing the 10 most recent of 33 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Delaware County?
Delaware County has a composite FEMA National Risk Index score of 82.7 out of 100, placing it in the Medium category and the 83th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Delaware County?
The three highest-rated hazards are Ice Storm (Very High, $2M EAL), Heat Wave (Medium, $2M EAL), Wildfire (Medium, $936K EAL). These account for most of the county's expected annual losses.
How does Delaware County compare to other Oklahoma counties?
Delaware County ranks #9 of 77 Oklahoma counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Delaware County had?
FEMA records 33 federal disaster declarations for Delaware County since 1973, most often 18 for severe storm events and 7 for severe ice storm events. The most recent was Severe Storms, Straight-Line Winds, Tornadoes, and Flooding, declared in June 2024.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Delaware County's $30M EAL is a statistical average, not a guarantee for any specific year or address.