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Potomac River at Hancock

Highest listed crest 47.60 ftFlood stage 25.0 ft55 crests since 1889

The Potomac River at Hancock crested at major flood stage 8 times among the 55 crests the National Weather Service lists from 1889 to 2025. The highest, 47.60 ft on March 18, 1936, was major flooding, 22.60 feet above flood stage. 6 other gauges on the Potomac River crested above flood stage within a week of it, 4 at their own highest listed crest.

The gauge

Highest listed crest
47.60 ft
March 18, 1936; 340,000 cubic feet per second
Flood stage
25.0 ft
Major flooding from 35.0 ft
Crests at major
8
9th of 108 gauges in Maryland
Most recent flood crest
May 15, 2025
26.30 ft, minor flooding
Location
Washington County
Maryland

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, Potomac River at Hancock
Action stage21.027Dec 16, 2018The level at which the NWS or its partners begin to take action
Flood stage (minor)25.019May 15, 2025Minimal or no property damage, but possibly some public threat
Moderate flood stage33.01May 1, 1889Some inundation of structures and roads near the stream
Major flood stage35.08Sep 8, 1996Extensive inundation of structures and roads

Every listed crest

55 crests from 1889 to 2025. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Potomac River at Hancock, 1889 to 2025 20304050ft Flood stage 25.0 ftMajor 35.0 ft May 1, 1889: 34.00 ft, moderate flooding; 22,000 cubic feet per secondJun 1, 1889: 40.00 ft, major flooding; 220,000 cubic feet per secondMar 30, 1924: 32.40 ft, minor flooding; 130,000 cubic feet per secondMay 13, 1924: 35.00 ft, major flooding; 160,000 cubic feet per secondApr 17, 1929: 30.30 ft, minor flooding; 110,000 cubic feet per secondApr 21, 1933: 23.10 ft, action stage; 64,400 cubic feet per secondMar 18, 1936: 47.60 ft, major flooding; 340,000 cubic feet per secondApr 27, 1937: 35.70 ft, major flooding; 153,000 cubic feet per secondOct 29, 1937: 31.80 ft, minor flooding; 122,000 cubic feet per secondFeb 4, 1939: 24.85 ft, action stage; 76,600 cubic feet per secondJun 1, 1940: 21.33 ft, action stage; 58,100 cubic feet per secondMay 23, 1942: 23.18 ft, action stage; 67,000 cubic feet per secondOct 16, 1942: 36.63 ft, major flooding; 155,000 cubic feet per secondSep 19, 1945: 21.98 ft, action stage; 61,000 cubic feet per secondApr 15, 1948: 22.27 ft, action stage; 62,500 cubic feet per secondJun 19, 1949: 26.86 ft, minor flooding; 88,400 cubic feet per secondJun 14, 1951: 23.61 ft, action stage; 67,300 cubic feet per secondApr 29, 1952: 21.89 ft, action stage; 58,600 cubic feet per secondMar 2, 1954: 24.52 ft, action stage; 72,100 cubic feet per secondAug 19, 1955: 32.40 ft, minor flooding; 123,000 cubic feet per secondMay 9, 1960: 26.60 ft, minor flooding; 80,600 cubic feet per secondFeb 20, 1961: 22.10 ft, action stage; 56,500 cubic feet per secondMar 22, 1962: 24.50 ft, action stage; 68,600 cubic feet per secondMar 21, 1963: 26.24 ft, minor flooding; 81,800 cubic feet per secondApr 30, 1964: 22.61 ft, action stage; 62,200 cubic feet per secondMar 8, 1967: 26.91 ft, minor flooding; 85,900 cubic feet per secondApr 3, 1970: 21.61 ft, action stage; 57,200 cubic feet per secondFeb 14, 1971: 22.91 ft, action stage; 63,600 cubic feet per secondJun 23, 1972: 30.79 ft, minor flooding; 112,000 cubic feet per secondApr 28, 1973: 21.06 ft, action stage; 54,600 cubic feet per secondDec 28, 1973: 23.19 ft, action stage; 65,100 cubic feet per secondMar 20, 1975: 25.44 ft, minor flooding; 77,200 cubic feet per secondJan 2, 1976: 21.71 ft, action stage; 57,700 cubic feet per secondOct 10, 1976: 28.56 ft, minor flooding; 96,700 cubic feet per secondMar 15, 1978: 23.73 ft, action stage; 68,800 cubic feet per secondFeb 27, 1979: 25.96 ft, minor flooding; 81,300 cubic feet per secondApr 25, 1983: 22.21 ft, action stage; 60,700 cubic feet per secondFeb 15, 1984: 25.64 ft, minor flooding; 79,500 cubic feet per secondNov 6, 1985: 41.20 ft, major flooding; 207,000 cubic feet per secondApr 18, 1987: 24.07 ft, action stage; 70,600 cubic feet per secondMay 7, 1988: 21.25 ft, action stage; 55,800 cubic feet per secondApr 17, 1993: 25.10 ft, minor flooding; 76,400 cubic feet per secondJan 20, 1996: 36.26 ft, major flooding; 152,000 cubic feet per secondSep 8, 1996: 35.81 ft, major flooding; 148,000 cubic feet per secondMar 22, 1998: 21.08 ft, action stage; 55,000 cubic feet per secondSep 20, 2003: 26.09 ft, minor flooding; 82,100 cubic feet per secondMar 29, 2005: 23.26 ft, action stage; 66,200 cubic feet per secondApr 16, 2007: 21.36 ft, action stage; 56,400 cubic feet per secondMay 5, 2009: 22.36 ft, action stage; 61,500 cubic feet per secondMar 14, 2010: 25.94 ft, minor flooding; 81,200 cubic feet per secondMay 19, 2011: 25.41 ft, minor floodingMay 17, 2014: 21.33 ft, action stage; 57,800 cubic feet per secondJun 4, 2018: 26.38 ft, minor flooding; 90,000 cubic feet per secondDec 16, 2018: 23.57 ft, action stage; 73,900 cubic feet per secondMay 15, 2025: 26.30 ft, minor flooding; 89,543 cubic feet per second Highest, 47.60 ft, Mar 18, 1936 1900192019401960198020002020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Potomac River at Hancock 1880s: 2 1890s: 0 1900s: 0 1910s: 0 1920s: 3 1930s: 3 1940s: 2 1950s: 1 1960s: 3 1970s: 4 4 1980s: 2 1990s: 3 2000s: 1 2010s: 3 2020s: 1 1880s1900s1920s1940s1960s1980s2000s2020s
  1. These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
  2. Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.

Highest crests

The 50 highest of 55 listed crests.

Highest listed crests, Potomac River at Hancock
1Mar 18, 193647.60+22.60Major340,000
2Nov 6, 198541.20+16.20Major207,000
3Jun 1, 188940.00+15.00Major220,000
4Oct 16, 194236.63+11.63Major155,000
5Jan 20, 199636.26+11.26Major152,000
6Sep 8, 199635.81+10.81Major148,000
7Apr 27, 193735.70+10.70Major153,000
8May 13, 192435.00+10.00Major160,000
9May 1, 188934.00+9.00Moderate22,000
10Mar 30, 192432.40+7.40Minor130,000
11Aug 19, 195532.40+7.40Minor123,000
12Oct 29, 193731.80+6.80Minor122,000
13Jun 23, 197230.79+5.79Minor112,000
14Apr 17, 192930.30+5.30Minor110,000
15Oct 10, 197628.56+3.56Minor96,700
16Mar 8, 196726.91+1.91Minor85,900
17Jun 19, 194926.86+1.86Minor88,400
18May 9, 196026.60+1.60Minor80,600
19Jun 4, 201826.38+1.38Minor90,000
20May 15, 202526.30+1.30Minor89,543
21Mar 21, 196326.24+1.24Minor81,800
22Sep 20, 200326.09+1.09Minor82,100
23Feb 27, 197925.96+0.96Minor81,300
24Mar 14, 201025.94+0.94Minor81,200
25Feb 15, 198425.64+0.64Minor79,500
26Mar 20, 197525.44+0.44Minor77,200
27May 19, 201125.41+0.41Minor—
28Apr 17, 199325.10+0.10Minor76,400
29Feb 4, 193924.85−0.15Action76,600
30Mar 2, 195424.52−0.48Action72,100
31Mar 22, 196224.50−0.50Action68,600
32Apr 18, 198724.07−0.93Action70,600
33Mar 15, 197823.73−1.27Action68,800
34Jun 14, 195123.61−1.39Action67,300
35Dec 16, 201823.57−1.43Action73,900
36Mar 29, 200523.26−1.74Action66,200
37Dec 28, 197323.19−1.81Action65,100
38May 23, 194223.18−1.82Action67,000
39Apr 21, 193323.10−1.90Action64,400
40Feb 14, 197122.91−2.09Action63,600
41Apr 30, 196422.61−2.39Action62,200
42May 5, 200922.36−2.64Action61,500
43Apr 15, 194822.27−2.73Action62,500
44Apr 25, 198322.21−2.79Action60,700
45Feb 20, 196122.10−2.90Action56,500
46Sep 19, 194521.98−3.02Action61,000
47Apr 29, 195221.89−3.11Action58,600
48Jan 2, 197621.71−3.29Action57,700
49Apr 3, 197021.61−3.39Action57,200
50Apr 16, 200721.36−3.64Action56,400

The worst floods along the Potomac River

For this gauge's highest crests, the other gauges on the Potomac River that crested above flood stage within a week.

March 18, 1936: 47.60 ft here, major flooding

November 6, 1985: 41.20 ft here, major flooding

June 1, 1889: 40.00 ft here, major flooding

Gauges on the Potomac River

Flood gauges sharing the river's name, linked within 80 miles of one another.

Flood gauges on the Potomac River
AlexandriaDC3.38.66 ft, Sep 19, 20032
Edwards FerryMD15.022.45 ft, Jun 5, 20180
Georgetown / Wisconsin AveDC6.017.72 ft, Oct 17, 19429
Hancock this gaugeMD25.047.60 ft, Mar 18, 19368
Harpers FerryMD18.036.50 ft, Mar 19, 193614
Lewisetta (IN MLLW)VA3.05.76 ft, Sep 1, 200611
Paw PawMD25.054.00 ft, Mar 18, 19368
Point of RocksMD16.041.03 ft, Mar 19, 193614
ShepherdstownWV15.042.07 ft, Mar 19, 193614
Washington DC (Little Falls)MD10.022.03 ft, Jun 24, 19724

Other gauges in Washington County

Flood gauges in Washington County
Sharpsburg8.016.73 ft, Jul 20, 19564
Waynesboro6.512.33 ft, Jun 22, 19721
Fairview10.024.50 ft, Jun 23, 19727
Pecktonville10.011.50 ft, May 14, 20250
Harpers Ferry18.036.50 ft, Mar 19, 193614
Bellegrove7.512.44 ft, Jun 22, 19720

Washington County: every hazard · River floods across the country · Maryland

NOAA National Water Prediction Service, gauge HNKM2, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.