Harris County, Texas Natural Disaster Risk
FEMA National Risk Index assessment · TX
Very HighComposite Risk Score
National percentile: 100th
Harris County faces very high composite natural disaster risk (NRI Risk Index score 99.9, 100th national percentile), driven primarily by hurricane and riverine flood exposure. Expected annual loss across all 18 hazard types is $2.22B.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Harris County carries a very high composite natural disaster risk, with a National Risk Index score of 99.9 out of 100 — placing it in the 100th national percentile and among the most at-risk counties in the United States. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
The county's risk is driven primarily by hurricane (tropical cyclones bringing extreme wind, rain, and storm surge) at Very High risk — $458M in expected annual loss and about 0.18 events per year; riverine flood (rivers and streams overflowing their banks after heavy rain or snowmelt) at Very High risk — $1.12B in expected annual loss and about 5.14 events per year; and tornado (violently rotating columns of air capable of catastrophic local damage) at Very High risk — $407M in expected annual loss and about 1.61 events per year. Across all hazards, FEMA estimates $2.22B in expected annual loss for a population of 4.73M.
Beyond physical exposure, Harris County has a 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: Harris County has received 41 federal disaster declarations since 1973, including 12 for hurricane events and 12 for flood events. The most recent was Hurricane Beryl (hurricane), declared in July 2024.
Among 254 Texas counties, Harris County ranks #1 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Hurricane | Very High | 0.18 / yr | $458M |
| Riverine Flood | Very High | 5.14 / yr | $1.12B |
| Tornado | Very High | 1.61 / yr | $407M |
| Cold Wave | Very High | 0.48 / yr | $118M |
| Lightning | Very High | 74.62 / yr | $9M |
| Heat Wave | Very High | 14.86 / yr | $80M |
| Ice Storm | Very High | 0.91 / yr | $4M |
| Strong Wind | Very High | 1.52 / yr | $8M |
| Earthquake | Medium | 0.00 / yr | $6M |
| Hail | Medium | 2.35 / yr | $2M |
| Winter Weather | High | 1.12 / yr | $296K |
| Landslide | Medium | 0.24 / yr | $37K |
| Wildfire | Low | 0.00 / yr | $562K |
| Coastal Flood | High | 3.76 / yr | $3M |
| Drought | Medium | 15.94 / yr | $550K |
| Avalanche | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
Disaster History
Harris County has received 41 federal disaster declarations since 1973, most recently Hurricane Beryl in July 2024. Most frequent causes: Hurricane (12), Flood (12), Severe Storm (8).
| Declared | Type | Disaster |
|---|---|---|
| July 2024 | Hurricane | Hurricane Beryl |
| May 2024 | Flood | Severe Storms, Straight-Line Winds, Tornadoes, and Flooding |
| February 2021 | Severe Ice Storm | Severe Winter Storms |
| February 2021 | Severe Ice Storm | Severe Winter Storm |
| August 2020 | Hurricane | Tropical Storms Marco and Laura |
| July 2020 | Hurricane | Hurricane Hanna |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2019 | Flood | Tropical Storm Imelda |
| August 2017 | Hurricane | Hurricane Harvey |
Showing the 10 most recent of 41 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Harris County?
Harris County has a composite FEMA National Risk Index score of 99.9 out of 100, placing it in the Very High category and the 100th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Harris County?
The three highest-rated hazards are Hurricane (Very High, $458M EAL), Riverine Flood (Very High, $1.12B EAL), Tornado (Very High, $407M EAL). These account for most of the county's expected annual losses.
How does Harris County compare to other Texas counties?
Harris County ranks #1 of 254 Texas counties for overall natural disaster risk, with a very high rating.
How many federally declared disasters has Harris County had?
FEMA records 41 federal disaster declarations for Harris County since 1973, most often 12 for hurricane events and 12 for flood events. The most recent was Hurricane Beryl, declared in July 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. Harris County's $2.22B EAL is a statistical average, not a guarantee for any specific year or address.