Merrimack County, New Hampshire
County storm and disaster record · FIPS 33013 · population 153,727 · 933 sq mi
NOAA's Storm Events Database holds 774 records for Merrimack County, New Hampshire from 1950 through June 30, 2026, on 514 days; the most frequent are severe thunderstorm wind events (242 records). The deadliest single record is the March 7, 1999 strong wind, filed for the forecast zone Merrimack, which covers the county: 1 death and 1 injury. FEMA has issued 29 declarations naming the county since 1973, 27 of them for natural hazards; the latest for a natural hazard was “Severe Storm and Flooding” on January 2, 2018.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 774on 514 days, 1950 to June 30, 2026
- Deaths recorded
- 220 injuries
- Damage, 2025 dollars
- $42Mas filed (scale steps before 1993)
- Tornadoes
- 7strongest EF2
- FEMA declarations
- 29latest 2020
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Merrimack County most?
The most frequent records are severe thunderstorm wind events: 242 since 1962. 65% of its severe thunderstorm wind events since 1962 fell in June and July. The rank column places the county among New Hampshire's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 242 | 123 | 1962-2026 | 1 | 0 | $54K | 7 of 10 |
| Winter storms | 187 | 186 | 1996-2026 | 0 | 1 | $8.8M | 7 of 10 |
| Floods | 111 | 75 | 1996-2025 | 0 | 0 | $15M | 3 of 10 |
| Hail | 101 | 53 | 1962-2026 | 0 | 0 | $100 | 7 of 10 |
| High wind and dust storms | 53 | 49 | 1996-2017 | 1 | 3 | $165K | 7 of 10 |
| Extreme cold | 22 | 21 | 1998-2023 | 0 | 0 | – | 6 of 10 |
| Drought | 21 | 21 | 1999-2026 | 0 | 0 | $11M | 5 of 10 |
| Lightning | 20 | 19 | 1997-2025 | 0 | 5 | $6.7M | 7 of 10 |
| Tornadoes | 7 | 7 | 1967-2018 | 0 | 10 | $433K | 8 of 10 |
| Heat | 3 | 3 | 1998-2024 | 0 | 0 | – | 7 of 10 |
| Fog, smoke and funnel clouds | 3 | 3 | 1999-2019 | 0 | 0 | – | 3 of 10 |
| Heavy rain | 2 | 2 | 1996-1999 | 0 | 0 | – | 6 of 10 |
| Hurricanes and tropical storms | 2 | 2 | 2011-2020 | 0 | 1 | $6K | 7 of 10 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
How many tornadoes has Merrimack County had?
NOAA records 7 tornadoes in Merrimack County from 1967 to 2018, the strongest rated EF2, with 0 deaths and 10 injuries recorded in the county. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 7 tornadoes whose track touched Merrimack County since 1950 (NOAA's county records number 7, the same count); along their whole tracks they killed 1 person, 0 of them in Merrimack County.
| Date | Tornado | Rating | Path | Killed |
|---|---|---|---|---|
| 2008-07-24 09:30, as SPC files it | Unnamed | EF2 | 50.46 mi | 1 |
Map of the strongest tornado tracks in New Hampshire.
Every tornado record filed for Merrimack County (7)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2018-05-04 | Box Corner, Merrimack County | EF1 16.2 mi x 300 yd | 0 | 0 | – |
| 2015-07-30 | Warner, Merrimack County | EF0 0.42 mi x 100 yd | 0 | 0 | – |
| 2008-07-24 | Epsom, Merrimack County | EF2 5.25 mi x 880 yd | 0 | 0 | $210K |
| 1999-07-06 | Pittsfield, Merrimack County | F1 1 mi x 75 yd | 0 | 0 | – |
| 1976-08-15 | Merrimack County | F1 | 0 | 5 | – |
| 1972-05-31 | Merrimack County | F1 0.1 mi x 50 yd | 0 | 0 | $250 step |
| 1967-07-12 | Merrimack County | F1 0.5 mi x 30 yd | 0 | 5 | $25K step |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Merrimack County?
The most recent record with damage, injuries or deaths is the September 6, 2025 thunderstorm wind ($2,000 in damage in 2025 dollars).
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-06-26 | Thunderstorm WindMartin, Merrimack County | 52 kt wind | 0 | 0 | – |
| 2026-06-26 | Thunderstorm WindHopkinton, Merrimack County | 52 kt wind | 0 | 0 | – |
| 2026-06-26 | Thunderstorm WindWarner, Merrimack County | 52 kt wind | 0 | 0 | – |
| 2026-06-26 | Thunderstorm WindRoby, Merrimack County | 52 kt wind | 0 | 0 | – |
| 2026-06-26 | Thunderstorm WindBlodgett Lndg, Merrimack County | 52 kt wind | 0 | 0 | – |
| 2026-06-26 | HailBow Mills, Merrimack County | 1.00 in hail | 0 | 0 | – |
| 2026-06-26 | HailHopkinton, Merrimack County | 1.00 in hail | 0 | 0 | – |
| 2026-06-26 | HailDavisville, Merrimack County | 2.00 in hail | 0 | 0 | – |
| 2026-06-26 | HailHastings, Merrimack County | 1.75 in hail | 0 | 0 | – |
| 2026-06-26 | HailPembroke, Merrimack County | 1.00 in hail | 0 | 0 | – |
| 2026-06-18 | Thunderstorm WindNorthfield, Merrimack County | 52 kt wind | 0 | 0 | – |
| 2026-05-01 | DroughtMerrimack County · forecast zone Merrimack | 0 | 0 | – |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1999-03-07 | Strong WindMerrimack County · forecast zone Merrimack A strong wind gust reportedly blew a compact car off the roadway on Route 3-A in the town of Hill. The single car accident resulted in one fatality and one injury. A peak wind gust of 37 mph was reported in Concord near the time of the accident. | 1 | 1 | – | |
| 1994-08-21 | Thunderstorm WindMerrimack County Increasing winds capsized a sailboat during a boat race on Lake Sunnapee, drowning the captain. The winds, estimated at 50 mph, were apparently associated with a thunderstorm gust front. (M59O) | 1 | 0 | – | |
| 1976-08-15 | TornadoMerrimack County | F1 | 0 | 5 | – |
| 1967-07-12 | TornadoMerrimack County | F1 0.5 mi x 30 yd | 0 | 5 | $25K step |
| 2002-07-23 | LightningHooksett, Merrimack County Severe thunderstorms moving through central and southern New Hampshire knocked down trees and power lines and lightning from the storms caused several fires. Southeastern Rockingham County had the worst damage as numerous trees were downed by the thunderstorms. Trees were reported down in Alexandria, Gilford, ... | 0 | 2 | – | |
| 2025-06-06 | LightningHenniker, Merrimack County Thunderstorms moved through the Henniker area on the afternoon of June, 6th. The storms were not severe in nature, but a few where strong with abundant lightning. A women who was outside at the time of the storm was struck by lighting near a vehicle. She was last reported in critical condition. | 0 | 1 | – | |
| 2025-05-17 | LightningHooksett, Merrimack County A line of thunderstorms associated with a cold front and area of surface low pressure pushed through the state of New Hampshire on Saturday evening. A line of storms reached Hooksett, New Hampshire around 9 PM EDT. A pedestrian walking outside was struck by lightning, suffering serious injuries. | 0 | 1 | – | |
| 2012-10-29 | High WindMerrimack County · forecast zone Merrimack High winds associated with the remnants of Sandy knocked down trees and branches and caused widespread power outages causing an estimated $106,000 in damages. | 50 kt wind | 0 | 1 | $136K |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1998-01-07 | Ice StormMerrimack County · forecast zone Merrimack | 0 | 0 | $6.6M | |
| 1997-07-09 | LightningBradford, Merrimack County | 0 | 0 | $5.5M | |
| 1996-10-20 | Flash FloodCountywide, Merrimack County | 0 | 0 | $4.1M | |
| 2010-02-25 | FloodSouth Hooksett, Merrimack County | 0 | 0 | $2.3M | |
| 2008-12-11 | Ice StormMerrimack County · forecast zone Merrimack | 0 | 0 | $2.2M | |
| 2011-08-28 | FloodMartin, Merrimack County | 0 | 0 | $1.2M | |
| 2006-05-13 | FloodCountywide, Merrimack County | 0 | 0 | $1.1M | |
| 2010-03-14 | FloodSouth Hooksett, Merrimack County | 0 | 0 | $595K |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $25K, in the dollars of the day) holds: July 12, 1967 (tornado, Merrimack County).
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Merrimack County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 0 | 3 | 10 | 15 | 36 | 44 | 89 | 45 |
| Winter storms | – | – | – | – | 31 | 89 | 43 | 24 |
| Floods | – | – | – | – | 4 | 35 | 47 | 25 |
| Hail | 0 | 2 | 1 | 2 | 6 | 42 | 20 | 28 |
| High wind and dust storms | – | – | – | – | 15 | 29 | 9 | 0 |
| Extreme cold | – | – | – | – | 7 | 13 | 0 | 2 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
65% of its severe thunderstorm wind events since 1962 fell in June and July. The two busiest months are in violet.
The values, month by month
Jan 70 · Feb 60 · Mar 58 · Apr 36 · May 60 · Jun 112 · Jul 160 · Aug 73 · Sep 26 · Oct 29 · Nov 26 · Dec 64 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Merrimack County
FEMA's register lists 29 declarations that include Merrimack County: 18 major disasters, 11 emergencies and 0 fire management assistance declarations. Most were for severe storm (12) and snowstorm (5).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2020-04-03 | DR-4516 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3445 | Biological | Covid-19 |
| 2018-01-02 | DR-4355 | Severe Storm | Severe Storm and Flooding |
| 2013-03-19 | DR-4105 | Severe Storm | Severe Winter Storm and Snowstorm |
| 2012-10-30 | EM-3360 | Hurricane | Hurricane Sandy |
| 2011-11-01 | EM-3344 | Severe Storm | Severe Storm |
| 2011-09-03 | DR-4026 | Hurricane | Tropical Storm Irene |
| 2011-08-27 | EM-3333 | Hurricane | Hurricane Irene |
| 2010-03-29 | DR-1892 | Severe Storm | Severe Winter Storm |
| 2009-01-02 | DR-1812 | Severe Ice Storm | Severe Winter Storm |
| 2008-12-13 | EM-3297 | Severe Storm | Severe Winter Storm |
| 2008-10-03 | DR-1799 | Severe Storm | Severe Storms and Flooding |
| 2008-08-11 | DR-1782 | Severe Storm | Severe Storms, Tornado, and Flooding |
| 2007-04-27 | DR-1695 | Severe Storm | Severe Storms and Flooding |
| 2006-05-25 | DR-1643 | Severe Storm | Severe Storms and Flooding |
| 2005-10-26 | DR-1610 | Severe Storm | Severe Storms and Flooding |
| 2005-09-19 | EM-3258 | Hurricane | Hurricane Katrina Evacuation |
| 2005-03-30 | EM-3207 | Snowstorm | Record and/Or Near Record Snow |
| 2004-01-15 | EM-3193 | Snowstorm | Snow |
| 2003-03-11 | EM-3177 | Snowstorm | Snow |
| 2001-03-28 | EM-3166 | Snowstorm | Snow |
| 1998-07-02 | DR-1231 | Severe Storm | Severe Storms and Flooding |
| 1998-01-15 | DR-1199 | Severe Storm | Severe Ice Storm, Rains and High Winds |
| 1996-10-29 | DR-1144 | Flood | Fall Northeaster Rainstorm |
| 1996-01-03 | DR-1077 | Flood | Excessive Rainfall, High Winds, and Flooding |
| 1993-03-16 | EM-3101 | Snowstorm | Blizzards, High Winds & Record Snowfall |
| 1990-08-29 | DR-876 | Flood | Severe Storms & Flooding |
| 1987-04-16 | DR-789 | Flood | Severe Storms & Flooding |
| 1973-07-11 | DR-399 | Flood | Severe Storms & Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
How many floods has Merrimack County had?
NOAA's Storm Events Database holds 111 flood or flash flood records for Merrimack County from 1996 to 2025, on 75 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Merrimack County ranks 747th of 2,942 U.S. counties.
| Storm | Began | Records | Deaths in the county |
|---|---|---|---|
| Tropical Storm Irene | 2011-08-28 | 1 | 0 |
| Hurricane Irene | 2011-08-28 | 1 | 0 |
The National Flood Insurance Program has paid $6.3 million on 299 claims filed in Merrimack County; the most in one year was 89 in 2006. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1978: 3 · 1979: 4 · 1980: 2 · 1981: 4 · 1982: 3 · 1983: 3 · 1984: 14 · 1986: 1 · 1987: 19 · 1988: 1 · 1992: 1 · 1995: 1 · 1996: 4 · 1998: 5 · 1999: 1 · 2001: 1 · 2003: 2 · 2004: 2 · 2005: 17 · 2006: 89 · 2007: 75 · 2008: 10 · 2009: 1 · 2010: 13 · 2011: 6 · 2013: 2 · 2014: 3 · 2015: 1 · 2016: 1 · 2017: 2 · 2018: 3 · 2021: 3 · 2022: 1 · 2023: 1; the other years: 0.
Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.
FEMA's modeled risk for Merrimack County
FEMA's National Risk Index rates Merrimack County Relatively Low overall, with an expected annual loss of $48.8 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Ice Storm | Relatively High | $1.1M | 1.8 a year (modeled) |
| Lightning | Relatively High | $1.4M | 21 a year (modeled) |
| Riverine Flooding | Relatively Moderate | $34M | 2.6 a year (modeled) |
| Hurricane | Relatively Moderate | $4.5M | once in about 12 years (modeled) |
| Winter Weather | Relatively Moderate | $268K | 19 a year (modeled) |
| Strong Wind | Relatively Moderate | $748K | about once a year (modeled) |
| Landslide | Relatively Low | $23K | 1.3 a year (modeled) |
| Earthquake | Relatively Low | $1.5M | once in about 608 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Merrimack County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in New HampshireEvery New Hampshire tornado since 1950 and the counties with the most per square mile
- Severe thunderstorm wind in New HampshireThe state's severe thunderstorm wind events, by county, year and month
- The New Hampshire recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Merrimack CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Merrimack County's FEMA declarations (CSV)29 rows: every declaration that named the county, for your own analysis