Merrimack County, New Hampshire severe weather history spans 460 recorded events between 1962 and 2025. The dominant hazard is thunderstorm wind, accounting for 50.7% of all recorded events. It ranks #1,018 nationally and #5 in New Hampshire.
460
Recorded events
1
Direct deaths
15
Direct injuries
$12.1M
Property damage
The record
What the Merrimack County, New Hampshire severe weather history record shows
Across the archive, Merrimack County, New Hampshire severe weather history averages 7.3 recorded events a year. The busiest stretch on record is the 2010s, with 156 events logged in that decade alone. Roughly 36 events fall before 1990 and 424 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Merrimack County, New Hampshire record is thunderstorm wind, responsible for 1 direct deaths. The costliest is flood, with $5.0M in reported property damage. In total, 7 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Merrimack County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Thunderstorm Wind | 233 | 1 | $44K | 78 | 1962–2025 |
| Hail | 96 | 0 | $100 | 2 | 1962–2025 |
| Flood | 73 | 0 | $5.0M | 0 | 2006–2025 |
| Flash Flood | 29 | 0 | $3.1M | 0 | 1996–2025 |
| Lightning | 20 | 0 | $3.7M | 0 | 1997–2025 |
| Tornado | 7 | 0 | $178K | F1 | 1967–2018 |
| Funnel Cloud | 2 | 0 | $0 | 0 | 2007–2019 |
Decade by decade
Merrimack County, New Hampshire severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
6 mapped tornado paths intersect this county: 4 touched down inside it and 2 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2008-07-24 | EF2 | 1 | 2 | 50.5 mi | Crossed in |
| 1999-07-06 | EF2 | 0 | 0 | 7.5 mi | Touched down here |
| 2018-05-04 | EF1 | 0 | 0 | 37.6 mi | Crossed in |
| 1972-05-31 | EF1 | 0 | 0 | 0.1 mi | Touched down here |
| 1967-07-12 | EF1 | 0 | 5 | 0.5 mi | Touched down here |
| 2015-07-30 | EF0 | 0 | 0 | 0.4 mi | Touched down here |
Significant events
Deadliest events on record in Merrimack County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Aug 21, 1994 | Thunderstorm Wind | 1 | 0 | $0 | |
| Aug 15, 1976 | Tornado | 0 | 5 | $0 | |
| Jul 12, 1967 | Tornado | 0 | 5 | $25K | |
| Jul 23, 2002 | Lightning | HOOKSETT | 0 | 2 | $0 |
| Jun 6, 2025 | Lightning | HENNIKER | 0 | 1 | $0 |
| May 18, 2025 | Lightning | HOOKSETT | 0 | 1 | $0 |
| Jun 16, 1998 | Lightning | BOW CENTER | 0 | 1 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
An E-F2 tornado moving north northeast out of Rockingham County crossed into Merrimack County near Route 202 and continued north northeast a little over 5 miles before entering Belknap County. Homes and buildins in the tornadoes path sustained damage along the path which was up to a half mile wide.
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.
In Henniker, highway and road management reported road damage from flooding along Bear Hill Road, Ray Road, Hemlock Corner Loop and parts of Dodge Hill Road due to heavy downpours dropping around 3 inches of rain on saturated soils.
Context
Risk, population and federal disasters
Relatively Low
FEMA NRI risk rating
155,967
Population (ACS)
$368K
Median home value
29
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Apr 3, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
| Jan 2, 2018 | Severe Storm | SEVERE STORM AND FLOODING | DR |
| Mar 19, 2013 | Severe Storm | SEVERE WINTER STORM AND SNOWSTORM | DR |
| Oct 30, 2012 | Hurricane | HURRICANE SANDY | EM |
| Nov 1, 2011 | Severe Storm | SEVERE STORM | EM |
Within the county
Most affected places
- North Chichester 106
Quick answers
Frequently asked
How many severe weather events have been recorded in Merrimack County, New Hampshire?
460 events are on record between 1962 and 2025, causing 1 direct deaths and $12.1M in property damage.
What is the most common severe weather hazard in Merrimack County?
Thunderstorm Wind, with 233 recorded events — 50.7% of everything in the archive for this county.
How many tornadoes have crossed Merrimack County?
6 mapped tornado paths intersect the county boundary; 4 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Merrimack County?
29 federal disaster declarations from FEMA include Merrimack County, each tied to a specific incident period.
How risky is Merrimack County compared with the rest of the country?
FEMA's National Risk Index rates Merrimack County as relatively low risk, placing it in the 78 percentile of its state for expected annual loss.
Where does the Merrimack County, New Hampshire severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Hillsborough County 507
- Rockingham County 537
- Grafton County 775
- Strafford County 256
- Coos County 364
- Sullivan County 263
Cite this page
“Merrimack County, New Hampshire.” Severe Weather History. severeweatherhistory.com/county/new-hampshire/merrimack-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.