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Lehigh River at Bethlehem

Highest listed crest 25.90 ftFlood stage 16.0 ft20 crests since 1902

The Lehigh River at Bethlehem crested at major flood stage 3 times among the 20 crests the National Weather Service lists from 1902 to 2021. The highest, 25.90 ft on May 23, 1942, was major flooding, 9.90 feet above flood stage. 2 other gauges on the Lehigh River crested above flood stage within a week of it, 1 at its own highest listed crest.

The gauge

Highest listed crest
25.90 ft
May 23, 1942; 92,000 cubic feet per second
Flood stage
16.0 ft
Major flooding from 22.0 ft
Crests at major
3
68th of 170 gauges in Pennsylvania
Most recent flood crest
September 2, 2021
19.53 ft, minor flooding
Location
Lehigh County
Near Bethlehem (1.0 mi), Allentown (5.4 mi), Northampton (7.6 mi)

Flood stages

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

Flood categories, Lehigh River at Bethlehem
Action stage12.04Dec 2, 1996The level at which the NWS or its partners begin to take action
Flood stage (minor)16.010Sep 2, 2021Minimal or no property damage, but possibly some public threat
Moderate flood stage20.01Jun 23, 1972Some inundation of structures and roads near the stream
Major flood stage22.03Aug 19, 1955Extensive inundation of structures and roads

Every listed crest

20 crests from 1902 to 2021. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Lehigh River at Bethlehem, 1902 to 2021 1015202530ft Flood stage 16.0 ftMajor 22.0 ft Feb 28, 1902: 24.90 ft, major flooding; 88,000 cubic feet per secondAug 24, 1933: 18.70 ft, minor flooding; 64,800 cubic feet per secondJul 10, 1935: 18.53 ft, minor flooding; 63,700 cubic feet per secondMar 12, 1936: 17.04 ft, minor flooding; 55,700 cubic feet per secondMay 23, 1942: 25.90 ft, major flooding; 92,000 cubic feet per secondDec 5, 1950: 15.31 ft, action stage; 46,900 cubic feet per secondNov 22, 1952: 13.75 ft, action stage; 41,200 cubic feet per secondAug 19, 1955: 23.38 ft, major flooding; 91,300 cubic feet per secondJun 23, 1972: 20.02 ft, moderate flooding; 57,900 cubic feet per secondJan 25, 1979: 17.12 ft, minor flooding; 51,700 cubic feet per secondJan 20, 1996: 16.68 ft, minor flooding; 44,900 cubic feet per secondJan 28, 1996: 15.57 ft, action stageDec 2, 1996: 12.72 ft, action stage; 32,000 cubic feet per secondSep 18, 2004: 19.70 ft, minor flooding; 56,700 cubic feet per secondApr 3, 2005: 16.06 ft, minor flooding; 42,632 cubic feet per secondJun 28, 2006: 17.74 ft, minor flooding; 49,000 cubic feet per secondMar 11, 2011: 17.17 ft, minor flooding; 46,800 cubic feet per secondAug 28, 2011: 11.91 ft, below flood stageSep 9, 2011: 11.45 ft, below flood stage; 26,700 cubic feet per secondSep 2, 2021: 19.53 ft, minor flooding; 56,020 cubic feet per second Highest, 25.90 ft, May 23, 1942 192019401960198020002020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Lehigh River at Bethlehem 1900s: 1 1910s: 0 1920s: 0 1930s: 3 3 1940s: 1 1950s: 1 1960s: 0 1970s: 2 1980s: 0 1990s: 1 2000s: 3 2010s: 1 2020s: 1 1900s1910s1920s1930s1940s1950s1960s1970s1980s1990s2000s2010s2020s
  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

Highest listed crests, Lehigh River at Bethlehem
1May 23, 194225.90+9.90Major92,000
2Feb 28, 190224.90+8.90Major88,000
3Aug 19, 195523.38+7.38Major91,300
4Jun 23, 197220.02+4.02Moderate57,900
5Sep 18, 200419.70+3.70Minor56,700
6Sep 2, 202119.53+3.53Minor56,020
7Aug 24, 193318.70+2.70Minor64,800
8Jul 10, 193518.53+2.53Minor63,700
9Jun 28, 200617.74+1.74Minor49,000
10Mar 11, 201117.17+1.17Minor46,800
11Jan 25, 197917.12+1.12Minor51,700
12Mar 12, 193617.04+1.04Minor55,700
13Jan 20, 199616.68+0.68Minor44,900
14Apr 3, 200516.06+0.06Minor42,632
15Jan 28, 199615.57−0.43Action—
16Dec 5, 195015.31−0.69Action46,900
17Nov 22, 195213.75−2.25Action41,200
18Dec 2, 199612.72−3.28Action32,000
19Aug 28, 201111.91−4.09Below flood stage—
20Sep 9, 201111.45−4.55Below flood stage26,700

The worst floods along the Lehigh River

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

May 23, 1942: 25.90 ft here, major flooding

  • LehightonPA · May 23, 1942 · 20.70 ft · Major
  • WalnutportPA · May 23, 1942 · 20.60 ft · Major · its highest

February 28, 1902: 24.90 ft here, major flooding

  • LehightonPA · Feb 28, 1902 · 20.80 ft · Major · its highest

August 19, 1955: 23.38 ft here, major flooding

  • LehightonPA · Aug 19, 1955 · 20.30 ft · Major
  • WalnutportPA · Aug 19, 1955 · 17.68 ft · Major

Gauges on the Lehigh River

In USGS station-number order, which runs downstream within a river basin.

Flood gauges on the Lehigh River
White HavenPA8.09.85 ft, Dec 21, 19571
LehightonPA10.020.80 ft, Feb 28, 19026
WalnutportPA8.020.60 ft, May 23, 19422
Bethlehem this gaugePA16.025.90 ft, May 23, 19423
GlendonPA19.027.90 ft, Apr 3, 200510

Other gauges in Lehigh County

Flood gauges in Lehigh County
Allentown8.011.82 ft, Aug 5, 20202
Allentown8.012.69 ft, Aug 4, 20201
Allentown5.012.76 ft, Aug 4, 20205
Trexlertown4.56.74 ft, Jan 10, 20240
Trexlertown4.56.70 ft, Jan 10, 20240

Lehigh County: every hazard · River floods across the country · Pennsylvania

NOAA National Water Prediction Service, gauge BETP1, 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.