73
Recorded events
0
Direct deaths
0
Direct injuries
$5.0M
Property damage
Flood in Merrimack County, New Hampshire: 73 recorded events between 2006 and 2025. The strongest on record measured 0. That places the county #126 nationally and #2 statewide for this hazard.
Decade by decade
Flood in Merrimack County, New Hampshire: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flood in Merrimack County is the 2010s, when 38 of the county's 73 recorded events were logged. Comparing decades is useful for spotting active periods, but the earliest years are thin because systematic reporting for this hazard began later.
Within the Merrimack County archive, flood makes up 15.9% of all recorded severe weather across 7 hazard types. Nationally the county sits at #126 for this hazard and #2 within New Hampshire, putting it in the 95.7 percentile of all U.S. counties.
Seasonality
Events by month
Apr is the peak month for flood in Merrimack County with 16 recorded events, while Jan is the quietest. Seasonality here is a property of the archive as much as the climate: reports cluster where population and spotter networks are densest.
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| May 31, 2025 | DAVISVILLE | 0 | $0 |
| May 31, 2025 | DAVISVILLE | 0 | $0 |
| May 31, 2025 | CONTOOCOOK | 0 | $0 |
| Jul 17, 2023 | NORTH CHICHESTER | 0 | $0 |
| Jul 11, 2023 | HENNIKER | 0 | $0 |
| Jul 11, 2023 | WEST SALISBURY | 0 | $0 |
| Jul 11, 2023 | DANBURY | 0 | $0 |
| Jul 3, 2023 | NORTH CHICHESTER | 0 | $0 |
| Dec 24, 2022 | WEST SALISBURY | 0 | $0 |
| Dec 24, 2022 | DAVISVILLE | 0 | $0 |
Other hazards here
More from Merrimack County
- Thunderstorm Wind 233
- Hail 96
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
The Blackwater River came out of banks and flooded portions of Route 4 in Andover between Plains Road and NH-11. The flooding was the result of multiple rounds of heavy rainfall over a 7 day period, tipped over into flooding by 1 to 3 inches of rainfall on the 10th. The river was slow to rise and slower to recede.
Strong low pressure moved north up the spine of the Appalachians and to the west of New Hampshire resulting in 2 to 2.5 inches of rain on partially frozen ground. Warm temperatures brought snowmelt which led to additional runoff. The Suncook River crested at minor flood stage on December 26th at 8.5 ft. The minor flood stage is 7 ft in N. Chichester. No significant impacts were reported with minor lowland flooding.
A late October storm produced 3 to 4 inches of rain across the region which resulted in flooding on the Suncook River at North Chichester. The river crested at 10.35 ft. (flood stage 7.0 ft). Flooding continued into the afternoon of the 1st.
Quick answers
Frequently asked
How many flood events are on record in Merrimack County, New Hampshire?
73 flood events are recorded in Merrimack County between 2006 and 2025, causing 0 direct deaths.
What is the strongest flood recorded in Merrimack County?
The strongest flood on record in Merrimack County measured 0.
Where does the flood data for Merrimack County come from?
All events come from the NOAA/NCEI Storm Events Database, the federal public-domain archive of severe weather reports. Dates are UTC, damage is as reported and not inflation-adjusted, and the most recent entries may still be revised.
Cite this page
“Flood in Merrimack County, New Hampshire.” Severe Weather History. severeweatherhistory.com/county/new-hampshire/merrimack-county/flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.