60
Recorded events
0
Direct deaths
1
Direct injuries
$10.1M
Property damage
Flash Flood in Coos County, New Hampshire: 60 recorded events between 1996 and 2024. The strongest on record measured 0. That places the county #461 nationally and #2 statewide for this hazard.
Decade by decade
Flash Flood in Coos County, New Hampshire: events per decade
Reporting practice changed over time — early decades are undercounted, not calmer.
The busiest decade for flash flood in Coos County is the 2020s, when 31 of the county's 60 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 Coos County archive, flash flood makes up 16.5% of all recorded severe weather across 8 hazard types. Nationally the county sits at #461 for this hazard and #2 within New Hampshire, putting it in the 84.9 percentile of all U.S. counties.
Seasonality
Events by month
Jul is the peak month for flash flood in Coos County with 32 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 |
|---|---|---|---|---|---|
| Jul 27, 2021 | LANCASTER | 0 | 0 | 1 | $20K |
Most recent
Latest recorded events
| Date | Location | Magnitude | Damage |
|---|---|---|---|
| Jul 11, 2024 | PITTSBURG | 0 | $0 |
| Jul 11, 2024 | PITTSBURG | 0 | $0 |
| Jul 11, 2024 | PITTSBURG | 0 | $0 |
| Jul 11, 2024 | KIDDERVILLE | 0 | $0 |
| Jul 11, 2024 | BERLIN | 0 | $0 |
| Jul 11, 2024 | LANCASTER | 0 | $0 |
| Jul 11, 2024 | SCOTT | 0 | $0 |
| Jul 11, 2024 | LANCASTER | 0 | $0 |
| Jul 11, 2024 | BERLIN | 0 | $0 |
| Jul 11, 2024 | DALTON | 0 | $0 |
Other hazards here
More from Coos County
- Thunderstorm Wind 175
- Hail 62
- Flood 51
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Significant damage occurred on the Peabody River on December 18th following a heavy rain and rapid snowmelt event. The USGS river gage in Gorham went from under 100 cfs around midnight, to over 13,000 cfs by noon. The streamflows were estimated to be around the 1% annual exceedance or 100-year flood level. Rainfall amounts where estimated around 5 inches with an additional 3 inches of rapid snowmelt runoff. The ground conditions were frozen, supporting complete runoff. One home off Route 16 was deemed unlivable and a complete loss after floodwaters eroded the foundation. Property was also damaged at Great Glen Trails Outdoor Center near the headwaters. Downstream in Gorham the damage was most prevalent along Bell Street and after the confluence with the Androscoggin River. Major damage occurred downstream to the town of Shelburne.
Multiple thunderstorms dropped 3 to 5 inches of rain in about 3 hours causing washouts and flooding on several roads in Randolph and Gorham. A wooden bridge was destroyed and a landslide closed a section of the Presidential Rail Trail in Gorham and Randolph. The flooded and washed out roads included Wood Spring Rd, Puggy Huddie Lane, and Pasture Path Rd. in Randolph and Mineral Spring Rd, Gorham Heights Rd, and Spring Rd. in Gorham.
Heavy rain produced flash flooding when Whipple Brook rapidly rose and went over its bank flooding a number of fields. It also flowed over Lost Nation Road and washed out the shoulder of the road. A highway manager said fill was needed in several areas along Lost Nation Road.
Quick answers
Frequently asked
How many flash flood events are on record in Coos County, New Hampshire?
60 flash flood events are recorded in Coos County between 1996 and 2024, causing 0 direct deaths.
What is the strongest flash flood recorded in Coos County?
The strongest flash flood on record in Coos County measured 0.
Where does the flash flood data for Coos 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 Coos County, New Hampshire.” Severe Weather History. severeweatherhistory.com/county/new-hampshire/coos-county/flash-flood/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.