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Merrimack River at Lowell

Highest listed crest 68.40 ftFlood stage 52.0 ft60 crests since 1852

The Merrimack River at Lowell crested at major flood stage 5 times among the 60 crests the National Weather Service lists from 1852 to 2025. The highest, 68.40 ft on March 20, 1936, was major flooding, 16.40 feet above flood stage. 5 other gauges on the Merrimack River crested above flood stage within a week of it, 5 at their own highest listed crest.

The gauge

Highest listed crest
68.40 ft
March 20, 1936; 173,000 cubic feet per second
Flood stage
52.0 ft
Major flooding from 58.0 ft
Crests at major
5
6th of 65 gauges in Massachusetts
Most recent flood crest
May 11, 2025
52.30 ft, minor flooding
Location
Middlesex County
Near Lowell (1.2 mi), Lawrence (7.9 mi), Methuen (9.0 mi)

Flood stages

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

Flood categories, Merrimack River at Lowell
Action stage50.025Mar 31, 2003The level at which the NWS or its partners begin to take action
Flood stage (minor)52.023May 11, 2025Minimal or no property damage, but possibly some public threat
Moderate flood stage54.06Apr 1, 2010Some inundation of structures and roads near the stream
Major flood stage58.05Apr 17, 2007Extensive inundation of structures and roads

Every listed crest

60 crests from 1852 to 2025. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Merrimack River at Lowell, 1852 to 2025 455055606570ft Flood stage 52.0 ftMajor 58.0 ft Apr 23, 1852: 60.60 ft, major flooding; 108,000 cubic feet per secondApr 8, 1924: 53.40 ft, minor flooding; 55,700 cubic feet per secondMar 31, 1925: 53.30 ft, minor flooding; 55,000 cubic feet per secondApr 27, 1926: 50.60 ft, action stage; 39,300 cubic feet per secondNov 5, 1927: 56.50 ft, moderate flooding; 76,800 cubic feet per secondMay 5, 1929: 50.20 ft, action stage; 37,000 cubic feet per secondJun 11, 1931: 50.00 ft, action stage; 35,900 cubic feet per secondApr 14, 1932: 52.60 ft, minor flooding; 50,700 cubic feet per secondApr 20, 1933: 56.00 ft, moderate flooding; 72,600 cubic feet per secondApr 14, 1934: 54.02 ft, moderate flooding; 59,600 cubic feet per secondJan 11, 1935: 52.40 ft, minor flooding; 49,500 cubic feet per secondMar 20, 1936: 68.40 ft, major flooding; 173,000 cubic feet per secondMay 16, 1937: 50.70 ft, action stage; 39,800 cubic feet per secondSep 23, 1938: 60.57 ft, major flooding; 121,100 cubic feet per secondApr 21, 1939: 51.56 ft, action stage; 48,600 cubic feet per secondApr 14, 1940: 52.93 ft, minor flooding; 55,800 cubic feet per secondJun 26, 1944: 51.77 ft, action stage; 49,200 cubic feet per secondMar 22, 1945: 50.14 ft, action stage; 39,500 cubic feet per secondMar 23, 1948: 52.28 ft, minor flooding; 51,700 cubic feet per secondApr 5, 1951: 52.63 ft, minor flooding; 53,900 cubic feet per secondApr 7, 1952: 52.59 ft, minor flooding; 53,700 cubic feet per secondMar 28, 1953: 52.93 ft, minor flooding; 56,000 cubic feet per secondMay 11, 1954: 51.70 ft, action stage; 47,900 cubic feet per secondApr 5, 1959: 51.62 ft, action stage; 47,400 cubic feet per secondApr 6, 1960: 56.00 ft, moderate flooding; 79,000 cubic feet per secondApr 2, 1962: 52.30 ft, minor flooding; 51,800 cubic feet per secondApr 4, 1967: 50.35 ft, action stage; 39,600 cubic feet per secondMar 23, 1968: 51.15 ft, action stage; 44,400 cubic feet per secondApr 24, 1969: 51.14 ft, action stage; 44,300 cubic feet per secondFeb 12, 1970: 50.87 ft, action stage; 42,700 cubic feet per secondApr 21, 1972: 50.08 ft, action stage; 36,600 cubic feet per secondApr 4, 1973: 51.47 ft, action stage; 44,800 cubic feet per secondDec 23, 1973: 51.75 ft, action stage; 46,600 cubic feet per secondApr 3, 1976: 51.27 ft, action stage; 42,000 cubic feet per secondMar 15, 1977: 53.41 ft, minor flooding; 58,000 cubic feet per secondJan 28, 1978: 52.26 ft, minor flooding; 50,000 cubic feet per secondMar 9, 1979: 51.22 ft, action stage; 43,300 cubic feet per secondApr 12, 1980: 50.80 ft, action stage; 40,700 cubic feet per secondFeb 27, 1981: 51.91 ft, action stage; 47,800 cubic feet per secondApr 20, 1982: 50.02 ft, action stage; 36,400 cubic feet per secondMar 21, 1983: 52.67 ft, minor flooding; 53,000 cubic feet per secondJun 1, 1984: 53.71 ft, minor flooding; 60,500 cubic feet per secondJan 29, 1986: 51.11 ft, action stage; 42,600 cubic feet per secondApr 7, 1987: 57.16 ft, moderate flooding; 84,700 cubic feet per secondMar 19, 1990: 50.26 ft, action stage; 37,700 cubic feet per secondApr 1, 1993: 52.31 ft, minor flooding; 50,000 cubic feet per secondNov 17, 1995: 49.40 ft, below flood stage; 33,180 cubic feet per secondApr 18, 1996: 53.05 ft, minor flooding; 54,800 cubic feet per secondOct 23, 1996: 53.10 ft, minor flooding; 48,600 cubic feet per secondJun 18, 1998: 52.74 ft, minor flooding; 50,400 cubic feet per secondApr 15, 2001: 50.95 ft, action stage; 40,200 cubic feet per secondMar 31, 2003: 50.38 ft, action stage; 37,200 cubic feet per secondApr 3, 2004: 52.80 ft, minor flooding; 50,800 cubic feet per secondApr 4, 2005: 52.77 ft, minor flooding; 50,600 cubic feet per secondMay 15, 2006: 58.84 ft, major flooding; 96,400 cubic feet per secondApr 17, 2007: 58.09 ft, major flooding; 89,800 cubic feet per secondMar 16, 2010: 53.63 ft, minor flooding; 56,400 cubic feet per secondApr 1, 2010: 54.64 ft, moderate flooding; 63,400 cubic feet per secondDec 20, 2023: 53.16 ft, minor flooding; 52,789 cubic feet per secondMay 11, 2025: 52.30 ft, minor flooding; 46,800 cubic feet per second Highest, 68.40 ft, Mar 20, 1936 1880192019602000

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Merrimack River at Lowell 1850s: 1 1860s: 0 1870s: 0 1880s: 0 1890s: 0 1900s: 0 1910s: 0 1920s: 3 1930s: 6 6 1940s: 2 1950s: 3 1960s: 2 1970s: 2 1980s: 3 1990s: 4 2000s: 4 2010s: 2 2020s: 2 1850s1870s1890s1910s1930s1950s1970s1990s2010s
  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 60 listed crests.

Highest listed crests, Merrimack River at Lowell
1Mar 20, 193668.40+16.40Major173,000
2Apr 23, 185260.60+8.60Major108,000
3Sep 23, 193860.57+8.57Major121,100
4May 15, 200658.84+6.84Major96,400
5Apr 17, 200758.09+6.09Major89,800
6Apr 7, 198757.16+5.16Moderate84,700
7Nov 5, 192756.50+4.50Moderate76,800
8Apr 20, 193356.00+4.00Moderate72,600
9Apr 6, 196056.00+4.00Moderate79,000
10Apr 1, 201054.64+2.64Moderate63,400
11Apr 14, 193454.02+2.02Moderate59,600
12Jun 1, 198453.71+1.71Minor60,500
13Mar 16, 201053.63+1.63Minor56,400
14Mar 15, 197753.41+1.41Minor58,000
15Apr 8, 192453.40+1.40Minor55,700
16Mar 31, 192553.30+1.30Minor55,000
17Dec 20, 202353.16+1.16Minor52,789
18Oct 23, 199653.10+1.10Minor48,600
19Apr 18, 199653.05+1.05Minor54,800
20Apr 14, 194052.93+0.93Minor55,800
21Mar 28, 195352.93+0.93Minor56,000
22Apr 3, 200452.80+0.80Minor50,800
23Apr 4, 200552.77+0.77Minor50,600
24Jun 18, 199852.74+0.74Minor50,400
25Mar 21, 198352.67+0.67Minor53,000
26Apr 5, 195152.63+0.63Minor53,900
27Apr 14, 193252.60+0.60Minor50,700
28Apr 7, 195252.59+0.59Minor53,700
29Jan 11, 193552.40+0.40Minor49,500
30Apr 1, 199352.31+0.31Minor50,000
31Apr 2, 196252.30+0.30Minor51,800
32May 11, 202552.30+0.30Minor46,800
33Mar 23, 194852.28+0.28Minor51,700
34Jan 28, 197852.26+0.26Minor50,000
35Feb 27, 198151.91−0.09Action47,800
36Jun 26, 194451.77−0.23Action49,200
37Dec 23, 197351.75−0.25Action46,600
38May 11, 195451.70−0.30Action47,900
39Apr 5, 195951.62−0.38Action47,400
40Apr 21, 193951.56−0.44Action48,600
41Apr 4, 197351.47−0.53Action44,800
42Apr 3, 197651.27−0.73Action42,000
43Mar 9, 197951.22−0.78Action43,300
44Mar 23, 196851.15−0.85Action44,400
45Apr 24, 196951.14−0.86Action44,300
46Jan 29, 198651.11−0.89Action42,600
47Apr 15, 200150.95−1.05Action40,200
48Feb 12, 197050.87−1.13Action42,700
49Apr 12, 198050.80−1.20Action40,700
50May 16, 193750.70−1.30Action39,800

The worst floods along the Merrimack River

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

March 20, 1936: 68.40 ft here, major flooding

  • NashuaNH · Mar 20, 1936 · 41.30 ft · Major · its highest
  • Franklin Jct.NH · Mar 19, 1936 · 36.40 ft · Major · its highest
  • Goffs FallsNH · Mar 20, 1936 · 35.19 ft · Major · its highest
  • ConcordNH · Mar 20, 1936 · 26.20 ft · Major · its highest
  • HaverhillMA · Mar 20, 1936 · 25.75 ft · Major · its highest

September 23, 1938: 60.57 ft here, major flooding

  • Franklin Jct.NH · Sep 22, 1938 · 29.50 ft · Major
  • Goffs FallsNH · Sep 23, 1938 · 25.87 ft · Major
  • ConcordNH · Sep 22, 1938 · 23.00 ft · Major
  • NashuaNH · Sep 23, 1938 · 30.50 ft · Moderate

May 15, 2006: 58.84 ft here, major flooding

  • Goffs FallsNH · May 15, 2006 · 19.87 ft · Major
  • HaverhillMA · May 15, 2006 · 17.05 ft · Major
  • NashuaNH · May 15, 2006 · 26.00 ft · Moderate
  • ConcordNH · May 15, 2006 · 15.12 ft · Minor

Gauges on the Merrimack River

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

Flood gauges on the Merrimack River
Franklin Jct.NH16.036.40 ft, Mar 19, 19363
ConcordNH14.026.20 ft, Mar 20, 19363
Goffs FallsNH11.035.19 ft, Mar 20, 19364
NashuaNH18.041.30 ft, Mar 20, 19361
Lowell this gaugeMA52.068.40 ft, Mar 20, 19365
LawrenceMA24.025.37 ft, Dec 20, 20230
HaverhillMA11.025.75 ft, Mar 20, 19363

Other gauges in Middlesex County

Flood gauges in Middlesex County
Maynard5.08.94 ft, Aug 20, 19556
Waltham5.07.56 ft, Mar 16, 20100
Lowell8.09.74 ft, Mar 17, 20100
East Pepperell8.019.10 ft, Mar 20, 19363
Wilmington7.010.54 ft, Mar 16, 20102
West Groton7.08.50 ft, Apr 17, 20070
Saxonville10.013.99 ft, Mar 31, 20103

Middlesex County: every hazard · River floods across the country · Massachusetts

NOAA National Water Prediction Service, gauge LOWM3, 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.