Johnson County, Tennessee Natural Disaster Risk
FEMA National Risk Index assessment · TN
Very LowComposite Risk Score
National percentile: 28th
Johnson County faces very low composite natural disaster risk (NRI Risk Index score 28.2, 28th national percentile), driven primarily by landslide and cold wave exposure. Expected annual loss across all 18 hazard types is $6M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Johnson County carries a very low composite natural disaster risk, with a National Risk Index score of 28.2 out of 100 — placing it in the 28th national percentile and among the lowest-risk counties in the country. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $39K in expected annual loss and about 0.87 events per year; cold wave (prolonged spells of dangerously low temperatures) at Low risk — $1M in expected annual loss and about 3.26 events per year; and wildfire (uncontrolled fires that spread across wildland and into communities) at Very Low risk — $39K in expected annual loss and about 0.00 events per year. Across all hazards, FEMA estimates $6M in expected annual loss for a population of 18K.
Beyond physical exposure, Johnson 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.
The county's disaster history tells the same story: Johnson County has received 20 federal disaster declarations since 1973, including 7 for severe storm events and 4 for flood events. The most recent was Severe Winter Storm (winter storm), declared in February 2026.
Among 95 Tennessee counties, Johnson County ranks #75 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 0.87 / yr | $39K |
| Cold Wave | Low | 3.26 / yr | $1M |
| Wildfire | Very Low | 0.00 / yr | $39K |
| Hurricane | Very Low | 0.02 / yr | $51K |
| Lightning | Low | 49.39 / yr | $137K |
| Drought | Low | 21.63 / yr | $79K |
| Riverine Flood | Low | 0.75 / yr | $4M |
| Earthquake | Very Low | 0.00 / yr | $147K |
| Ice Storm | Low | 0.31 / yr | $29K |
| Strong Wind | Low | 2.71 / yr | $228K |
| Winter Weather | Low | 17.43 / yr | $19K |
| Tornado | Very Low | 0.05 / yr | $236K |
| Hail | Very Low | 3.48 / yr | $29K |
| Heat Wave | Very Low | 0.00 / yr | $0 |
| 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
Johnson County has received 20 federal disaster declarations since 1973, most recently Severe Winter Storm in February 2026. Most frequent causes: Severe Storm (7), Flood (4), Winter Storm (2).
| Declared | Type | Disaster |
|---|---|---|
| February 2026 | Winter Storm | Severe Winter Storm |
| January 2026 | Winter Storm | Severe Winter Storm |
| April 2025 | Severe Storm | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| October 2024 | Tropical Storm | Tropical Storm Helene |
| September 2024 | Tropical Storm | Tropical Storm Helene |
| April 2023 | Severe Storm | Severe Storms, Straight-Line Winds, and Tornadoes |
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| April 2019 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| May 2011 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Associated Flooding |
Showing the 10 most recent of 20 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Johnson County?
Johnson County has a composite FEMA National Risk Index score of 28.2 out of 100, placing it in the Very Low category and the 28th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Johnson County?
The three highest-rated hazards are Landslide (Medium, $39K EAL), Cold Wave (Low, $1M EAL), Wildfire (Very Low, $39K EAL). These account for most of the county's expected annual losses.
How does Johnson County compare to other Tennessee counties?
Johnson County ranks #75 of 95 Tennessee counties for overall natural disaster risk, with a very low rating.
How many federally declared disasters has Johnson County had?
FEMA records 20 federal disaster declarations for Johnson County since 1973, most often 7 for severe storm events and 4 for flood events. The most recent was Severe Winter Storm, declared in February 2026.
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. Johnson County's $6M EAL is a statistical average, not a guarantee for any specific year or address.