107
Recorded events
2
Direct deaths
2
Direct injuries
$34.9M
Property damage
Flash Flood in Grafton County, New Hampshire: 107 recorded events between 1996 and 2024. The strongest on record measured 0. That places the county #145 nationally and #1 statewide for this hazard.
Decade by decade
Flash Flood in Grafton County, New Hampshire: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in Grafton County is the 2010s, when 53 of the county's 107 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 Grafton County archive, flash flood makes up 13.8% of all recorded severe weather across 9 hazard types. Nationally the county sits at #145 for this hazard and #1 within New Hampshire, putting it in the 95.3 percentile of all U.S. counties.
Seasonality
Events by month
Jul is the peak month for flash flood in Grafton County with 45 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.
Significant events
Deadliest on record
| Date | Location | Scale | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Jun 27, 1998 | PIERMONT | 0 | 1 | 1 | $1.5M |
| Jul 13, 1996 | BRISTOL | 0 | 1 | 0 | $0 |
| Jun 10, 2005 | COUNTYWIDE | 0 | 0 | 1 | $1.0M |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Aug 1, 2024 | EAST HAVERHILL | 0 | $0 |
| Aug 1, 2024 | EAST HAVERHILL | 0 | $0 |
| Jul 31, 2024 | PIKE | 0 | $0 |
| Jul 31, 2024 | WARREN MORSE FLD ARP | 0 | $0 |
| Jul 30, 2024 | LANDAFF | 0 | $0 |
| Jul 30, 2024 | LANDAFF | 0 | $0 |
| Jul 11, 2024 | LITTLETON | 0 | $0 |
| Jul 11, 2024 | TINKERVILLE | 0 | $0 |
| Jul 11, 2024 | LITTLETON | 0 | $0 |
| Jul 11, 2024 | PATTENVILLE | 0 | $0 |
Other hazards here
More from Grafton County
- Thunderstorm Wind 399
- Hail 132
- Flood 110
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Slow moving thunderstorms produced 4 to 7 inches of rain which fell in less than 6 hours, causing serious flash flooding. Many roads were flooded and destroyed. Several homes were also flooded and damaged. Groton and Orange New Hampshire were the most seriously affected. In Groton the Cockermouth River rose almost 8 feet in just over an hour, flooding much of Sculptured Rocks Road. Towns seriously affected were Campton, Canaan, Dorchester, Enfield, Grafton, Groton, Hebron, Orange, and Rumney.
Strong thunderstorms dropped 3 to 5 inches of rain in about 3 hours causing washouts and flooding on several roads in Haverhill and flooding two operating rooms at Cottage Hospital to a depth of 3 inches. The roads either flooded or washed out were: Ansley Rd, Daniels Rd, Court St, Country Land Drive, Brushwood Rd, Depot St, and Swiftwater Rd.
A stalled frontal boundary was the focus of thunderstorm activity during the early morning hours of the 29th. Two to four inches of heavy rain fell in a 3 hour period and produced flash flooding and road washouts on Route 118.
Quick answers
Frequently asked
How many flash flood events are on record in Grafton County, New Hampshire?
107 flash flood events are recorded in Grafton County between 1996 and 2024, causing 2 direct deaths.
What is the strongest flash flood recorded in Grafton County?
The strongest flash flood on record in Grafton County measured 0.
Where does the flash flood data for Grafton 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
“Flash Flood in Grafton County, New Hampshire.” Severe Weather History. severeweatherhistory.com/county/new-hampshire/grafton-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.