Rivers in New Hampshire

Connecticut River at Dalton

Coos County, New HampshireNWS DLTN3USGS 01131500Gray office

Below flood stage
7.07ftStage

Observed Wed, Sep 30, 12:15 AM EDT

Flood stage
18.00 ft
Forecast crest
7.20 ftWed, Sep 30, 2:00 AM EDT
Record crest
25.60 ft1936

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood23.00 ft
Moderate flood21.00 ft
Minor flood18.00 ft
Action15.00 ft
  1. 25.60 ftRecord flood comparable to the flood of 1936.
  2. 25.00 ftWater reaches US Route 2 Bridge Street in Lancaster, causing major regional travel disruptions. Floodwaters completely isolate several homes.
  3. 23.00 ftWater flows over US Route 3 in Lancaster near Industrial Park Road. Water also reaches US Route 2 Bridge Street.
  4. 22.00 ftRoute 135 in Dalton is inundated. Homes flood along Route 135 north of the Johns River.
  5. 21.00 ftIn Guildhall, VT, Route 102 floods just north of the Route 2 bridge to Lancaster, as well as near Breault Road at the Washburn Brook crossing. In Dalton, Route 135 floods at the public boat launch. Basements flood at a few residences along Route 135 north of the Johns River.
  6. 20.00 ftFloodwaters cut off access to a few homes along Route 135 in Lancaster. Several riverside camps along Route 135 north of the Johns River are flooded. River Road is underwater between the Mt. Orne Bridge and South Lunenburg.
  7. 19.00 ftBasements of low-lying homes in Dalton and Lancaster are at risk of flooding. Water begins to encroach on Route 135 at the Dalton public boat launch.
  8. 18.00 ftWater inundates campgrounds, agricultural fields, and recreational fields off Bridge Street in Lancaster.
  9. 17.00 ftMinor lowland flooding begins.

Flood outlook

Chance of flooding, October to December

CategoryChance
Minor floodingUnder 5%
Moderate floodingUnder 5%
Major floodingUnder 5%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 28, 2026.

Crest history

57 crests on NOAA’s list since 1936.

#DateStage
1March 20, 193625.60 ft
2April 1, 199823.70 ft
3March 19, 199023.22 ft
4March 28, 195322.38 ft
5April 24, 195422.25 ft
6April 17, 201422.15 ft
7April 29, 201122.07 ft
8April 16, 200221.40 ft
9April 25, 200121.38 ft
10May 6, 197221.34 ft
11May 4, 194021.10 ft
12October 18, 200521.10 ft
13April 25, 199620.86 ft
14January 17, 199520.73 ft
15April 23, 195820.63 ft
16April 19, 196920.58 ft
17April 2, 198720.54 ft
18June 1, 198420.30 ft
19April 20, 196020.26 ft
20April 17, 195520.19 ft
21April 7, 198920.16 ft
22April 18, 199420.06 ft
23April 24, 199219.79 ft
24March 31, 194519.79 ft
25April 25, 197419.78 ft

Most recent crests

  • July 13, 2024: 17.76 ft
  • March 8, 2024: 17.86 ft
  • December 20, 2023: 17.31 ft
  • April 17, 2014: 22.15 ft
  • May 26, 2013: 18.18 ft
  • April 29, 2011: 22.07 ft
  • April 21, 2008: 17.65 ft
  • April 25, 2007: 18.35 ft
  • October 18, 2005: 21.10 ft
  • April 6, 2005: 17.14 ft

Nearby

Upstream, downstream and the gauges around this one.

What this means

Forecasts by the Northeast River Forecast Center. Forecasts are issued routinely year-round.

Sources

Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.