Hillsborough County, NH
FEMA National Risk Index scores, disaster declarations & hazard data
Hillsborough County has experienced 31 federally declared disasters since 1973, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Hillsborough County's highest-rated hazards are ice storm, lightning, and inland flooding, with its top risk rated "Very High" by FEMA's National Risk Index. Recorded storm events have increased 300% over the past five years compared to the prior five-year period. Community vulnerability is relatively low (22nd percentile nationally), indicating stronger recovery capacity than most US counties.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Hillsborough County has been designated in 31 declarations since 1973, covering 6 disaster types including severe storm (13), snowstorm (6), flood (5).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2015 | Severe Storm | Severe Winter Storm And Snowstorm |
| 2013 | Severe Storm | Severe Winter Storm And Snowstorm |
| 2013 | Hurricane | Hurricane Sandy |
| 2012 | Severe Storm | Severe Storm And Snowstorm |
| 2012 | Severe Storm | Severe Storm |
| 2011 | Hurricane | Hurricane Irene |
| 2010 | Severe Storm | Severe Winter Storm |
| 2010 | Severe Storm | Severe Storms And Flooding |
Showing the 10 most recent of 31 total declarations since 1973.
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively Low | 67 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 92.6 | 52 | 0 | $1.4M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Relatively Low | 88.2 | — | — | — |
| Heat Wave | Relatively Low | 75.4 | 1 | 0 | — |
| Tornado | Relatively Moderate | 82.6 | 0 | 0 | — |
| Hurricane | Relatively Moderate | 92.6 | 0 | 0 | — |
| Hail | Relatively Low | 55.4 | 37 | 0 | $3K |
| Strong Wind | Relatively High | 86.9 | 0 | 0 | — |
| Winter Weather | Relatively High | 87.4 | 0 | 0 | — |
| Ice Storm | Very High | 95.4 | — | — | — |
| Cold Wave | Relatively Moderate | 66.2 | — | — | — |
| Lightning | Relatively High | 93.2 | 0 | 0 | — |
| Drought | Relatively Low | 57.9 | 0 | 0 | — |
| Landslide | Relatively Low | 84.2 | 0 | 0 | — |
| Avalanche | Very Low | 15.2 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Not Applicable | — | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Hillsborough County ranks in the 22nd percentile (Very low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 22nd | Very low |
| Socioeconomic status | 22nd | Very low |
| Household characteristics | 10th | Very low |
| Racial & ethnic minority status | 50th | Moderate |
| Housing type & transportation | 44th | Low |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 16th | Very Low |
| Risk to homes | 18th | Very Low |
| Buildings in direct exposure zone | 45.9% | — |
NOAA tracked 90 weather events in this county over 2016–2025: 18 in 2016–20 vs 72 in 2021–25 (+300% — frequency increasing).
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Hillsborough County?
According to the FEMA National Risk Index, the highest-risk hazards in Hillsborough County, New Hampshire are ice storm, lightning, and inland flooding. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has Hillsborough County received federal disaster declarations?
Yes. Hillsborough County has received 31 federal disaster declarations since 1973, including declarations in 2020. The most common disaster type on record is severe storm (13 declarations).
Has Hillsborough County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Hillsborough County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does Hillsborough County's natural hazard risk compare to nearby counties?
Among neighboring counties, Middlesex County, MA has the highest overall natural hazard risk (Relatively High) and Sullivan County, NH has the lowest (Very Low). Hillsborough County is rated Relatively Moderate overall.
How is Hillsborough County's composite disaster risk index calculated?
Hillsborough County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Hillsborough County's composite score of 90 means its overall natural hazard risk is higher than 90% of US counties.