Pemigewasset River at Plymouth, NH
River level and flood forecast · Grafton County
The river is 12.4 ft below flood stage (13 ft).
Forecast to rise to 2.3 ft Wed 2 PM, below the 13 ft flood stage.
Flow: 212 cubic feet per second (USGS).
Lower than normal for October 13.
Usual for October 13: 299 to 1,010 cubic feet per second (the middle half of 123 years).
The last 7 days and the forecast
NWS forecast issued Mon, Oct 12, 11:14 AM. Forecasts change as rain falls and as upstream water arrives.
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An email when the National Weather Service forecasts Pemigewasset River at Plymouth to flood, when it floods, and when it's over.
Flood stages
| Major flood stage | 21 ft |
| Moderate flood stage | 18 ft |
| Flood stage | 13 ft |
| Action stage | 10 ft |
| Record crest (March 19, 1936) | 29 ft |
What floods at each level
From the National Weather Service, highest first.
- 22 ftFlood waters 5 to 6 feet deep on route 175A in Holderness.
- 20.1 ftFlood waters rise to the doors of the PSU physical education center and the PSU ice arena.
- 18 ftSouth River Road and Avery Street flood in Holderness.
- 15.5 ftFlood waters over the road at the Irving station on route 175A in Holderness.
- 15 ftFlood waters up to the road at the Irving station on route 175A in Holderness.
- 14 ftWater enters the parking lot behind the PSU ice arena.
- 13 ftMinor lowland flooding begins.
Highest crests on record
- 29 ft — March 19, 1936
- 27.4 ft — November 4, 1927
- 23.62 ft — September 21, 1938
- 23.43 ft — April 1, 1987
- 22.68 ft — October 25, 1959
Recent crests: 16.08 ft (April 13, 2024) · 13.85 ft (March 7, 2024) · 20.58 ft (December 19, 2023) · 15.18 ft (December 24, 2022) · 19.77 ft (October 30, 2017)
Highest flow on record
65,400 cubic feet per second — March 19, 1936. From the USGS's yearly peaks since 1904.
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (PLMN3); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.