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Mississippi River at Alton

Highest listed crest 39.55 ftFlood stage 21.0 ft39 crests since 1993

The Mississippi River at Alton crested at major flood stage 7 times among the 39 crests the National Weather Service lists from 1993 to 2026. The highest, 39.55 ft on August 1, 1993, was major flooding, 18.55 feet above flood stage. 10 other gauges on the Mississippi River crested above flood stage within a week of it, 8 at their own highest listed crest.

The gauge

Highest listed crest
39.55 ft
August 1, 1993; 369,500 cubic feet per second
Flood stage
21.0 ft
Major flooding from 31.0 ft
Crests at major
7
39th of 177 gauges in Illinois
Most recent flood crest
May 1, 2026
21.54 ft, minor flooding
Location
Madison County
Near Alton (2.1 mi), Godfrey (5.0 mi), Wood River (5.9 mi)

Flood stages

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

Flood categories, Mississippi River at Alton
Action stage20.02Mar 29, 2020The level at which the NWS or its partners begin to take action
Flood stage (minor)21.016May 1, 2026Minimal or no property damage, but possibly some public threat
Moderate flood stage24.014Apr 3, 2019Some inundation of structures and roads near the stream
Major flood stage31.07Jun 9, 2019Extensive inundation of structures and roads

Every listed crest

39 crests from 1993 to 2026. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Mississippi River at Alton, 1993 to 2026 2025303540ft Flood stage 21.0 ftMajor 31.0 ft Aug 1, 1993: 39.55 ft, major flooding; 369,500 cubic feet per secondApr 14, 1994: 24.78 ft, moderate floodingMay 22, 1995: 31.43 ft, major floodingJun 2, 1996: 26.46 ft, moderate floodingMar 1, 1997: 23.26 ft, minor floodingApr 17, 1998: 24.74 ft, moderate floodingMay 2, 1999: 23.36 ft, minor floodingJun 9, 2001: 24.99 ft, moderate floodingApr 17, 2002: 28.27 ft, moderate floodingDec 28, 2005: 20.00 ft, action stageApr 13, 2008: 21.67 ft, minor floodingApr 28, 2008: 21.67 ft, minor floodingJun 29, 2008: 29.78 ft, moderate floodingSep 19, 2008: 25.95 ft, moderate floodingMay 4, 2009: 22.78 ft, minor floodingMay 21, 2009: 23.87 ft, minor floodingNov 2, 2009: 22.87 ft, minor floodingMar 30, 2010: 23.36 ft, minor floodingMay 19, 2010: 24.49 ft, moderate floodingJun 28, 2010: 26.01 ft, moderate floodingJul 24, 2010: 23.07 ft, minor floodingApr 30, 2011: 25.06 ft, moderate floodingJun 7, 2011: 22.99 ft, minor floodingJun 20, 2011: 24.45 ft, moderate floodingApr 25, 2013: 28.04 ft, moderate floodingJun 4, 2013: 31.27 ft, major floodingJul 11, 2014: 23.02 ft, minor floodingJun 30, 2015: 29.11 ft, moderate floodingJan 1, 2016: 31.94 ft, major floodingMay 6, 2017: 31.02 ft, major floodingOct 17, 2018: 23.71 ft, minor floodingApr 3, 2019: 28.77 ft, moderate floodingMay 7, 2019: 31.60 ft, major floodingJun 9, 2019: 35.30 ft, major floodingOct 13, 2019: 21.86 ft, minor floodingMar 29, 2020: 20.30 ft, action stageJun 1, 2020: 21.69 ft, minor floodingMar 20, 2021: 21.70 ft, minor floodingMay 1, 2026: 21.54 ft, minor flooding Highest, 39.55 ft, Aug 1, 1993 200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Mississippi River at Alton 1990s: 7 2000s: 9 2010s: 18 18 2020s: 3 1990s2000s2010s2020s
  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, Mississippi River at Alton
1Aug 1, 199339.55+18.55Major369,500
2Jun 9, 201935.30+14.30Major—
3Jan 1, 201631.94+10.94Major—
4May 7, 201931.60+10.60Major—
5May 22, 199531.43+10.43Major—
6Jun 4, 201331.27+10.27Major—
7May 6, 201731.02+10.02Major—
8Jun 29, 200829.78+8.78Moderate—
9Jun 30, 201529.11+8.11Moderate—
10Apr 3, 201928.77+7.77Moderate—
11Apr 17, 200228.27+7.27Moderate—
12Apr 25, 201328.04+7.04Moderate—
13Jun 2, 199626.46+5.46Moderate—
14Jun 28, 201026.01+5.01Moderate—
15Sep 19, 200825.95+4.95Moderate—
16Apr 30, 201125.06+4.06Moderate—
17Jun 9, 200124.99+3.99Moderate—
18Apr 14, 199424.78+3.78Moderate—
19Apr 17, 199824.74+3.74Moderate—
20May 19, 201024.49+3.49Moderate—
21Jun 20, 201124.45+3.45Moderate—
22May 21, 200923.87+2.87Minor—
23Oct 17, 201823.71+2.71Minor—
24May 2, 199923.36+2.36Minor—
25Mar 30, 201023.36+2.36Minor—
26Mar 1, 199723.26+2.26Minor—
27Jul 24, 201023.07+2.07Minor—
28Jul 11, 201423.02+2.02Minor—
29Jun 7, 201122.99+1.99Minor—
30Nov 2, 200922.87+1.87Minor—
31May 4, 200922.78+1.78Minor—
32Oct 13, 201921.86+0.86Minor—
33Mar 20, 202121.70+0.70Minor—
34Jun 1, 202021.69+0.69Minor—
35Apr 13, 200821.67+0.67Minor—
36Apr 28, 200821.67+0.67Minor—
37May 1, 202621.54+0.54Minor—
38Mar 29, 202020.30−0.70Action—
39Dec 28, 200520.00−1.00Action—

The worst floods along the Mississippi River

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

August 1, 1993: 39.55 ft here, major flooding

June 9, 2019: 35.30 ft here, major flooding

January 1, 2016: 31.94 ft here, major flooding

Gauges on the Mississippi River

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

Flood gauges on the Mississippi River
TiptonvilleMO37.048.35 ft, May 5, 20112
Alma - Pool 5MN672.0672.13 ft, Apr 16, 20010
Alton this gaugeIL21.039.55 ft, Aug 1, 19937
Baton RougeLA35.047.28 ft, May 15, 192731
BellevueIL17.023.51 ft, Apr 26, 196511
BrainerdMN16.017.61 ft, Jun 28, 20120
BrownsvilleMN635.0640.20 ft, Apr 22, 19650
BurlingtonIL15.025.73 ft, Jun 17, 200836
CamancheIA17.024.65 ft, Apr 28, 196520
Canton Lock and Dam 20MO15.027.88 ft, Jul 9, 19933
Cape GirardeauMO32.048.86 ft, Jan 2, 201615
CaruthersvilleMO32.047.61 ft, May 7, 20112
ChesterIL27.049.74 ft, Aug 7, 19939
Clarksville Lock and Dam 24MO25.037.73 ft, Jul 29, 199310
ClaytonIA620.0627.28 ft, Apr 24, 19650
DakotaMN644.0649.08 ft, Apr 21, 19650
DonaldsonvilleLA27.036.01 ft, May 15, 19273
Dubuque (LD11)IA16.025.69 ft, Apr 26, 196513
Dubuque (Railroad Bridge)IA17.026.81 ft, Apr 26, 196518
Fort RipleyMN10.514.15 ft, Apr 8, 19970
Fridley abv 37th Ave NEMN16.020.00 ft, Apr 17, 19656
FultonIL16.024.75 ft, Apr 28, 196513
GladstoneIL10.022.46 ft, Jun 17, 200824
GraftonIL20.038.17 ft, Aug 1, 199315
Gregory LandingMO15.028.49 ft, Jul 9, 19934
HannibalMO17.031.80 ft, Jul 15, 199310
HelenaAR44.060.21 ft, Feb 12, 19374
HerculaneumMO26.029.79 ft, Jul 10, 20240
HickmanKY34.054.29 ft, May 2, 20113
Hwy 169 at ChamplinMN12.017.96 ft, Apr 12, 19653
Hwy 610 in Brooklyn ParkMN12.019.53 ft, Apr 17, 19654
Illinois CityIA15.024.10 ft, Jul 9, 199321
KeithsburgIA14.024.49 ft, Jun 17, 200822
KeokukIA16.027.58 ft, Jul 10, 199324
La Crosse - Pool 8WI12.017.89 ft, Apr 22, 19654
LaGrangeMO17.030.00 ft, Jul 13, 19934
Lake CityWI16.022.18 ft, Apr 19, 19653
Lansing - Pool 9IA17.022.50 ft, Apr 24, 19651
LeClaireIA11.017.75 ft, Apr 28, 196516
LouisianaMO15.028.40 ft, Jul 28, 19934
McGregorIA16.025.38 ft, Apr 24, 19653
Mel Price (Alton) Lock and DamIL21.042.72 ft, Aug 1, 19938
MemphisTN34.048.70 ft, Feb 10, 19372
MuscatineIA16.025.61 ft, Jul 9, 199321
NatchezMS48.061.95 ft, May 19, 20116
New BostonIL15.025.90 ft, Jul 9, 199322
New MadridMO34.048.35 ft, May 6, 20114
New OrleansLA17.021.27 ft, Apr 25, 19225
OsceolaAR28.050.90 ft, Feb 7, 193742
QuincyIL19.032.13 ft, Jul 13, 19937
Quincy Lock and Dam 21IL18.031.30 ft, Jul 13, 19937
Red River LandingLA48.063.39 ft, May 18, 20110
Red WingMN14.020.70 ft, Apr 18, 19659
ReserveLA22.026.00 ft, Jun 11, 19291
Rock IslandIL15.022.70 ft, May 2, 201920
Saverton Lock and Dam 22MO16.029.58 ft, Jul 25, 19939
St. CloudMN9.011.44 ft, Apr 8, 19971
St. LouisMO30.049.58 ft, Aug 1, 19939
St. PaulMN14.026.01 ft, Apr 16, 196516
ThebesIL33.047.74 ft, Jan 2, 201612
Tunica Mhoon LandingMS30.053.20 ft, Feb 10, 19375
VicksburgLA43.057.10 ft, May 19, 201112
Wabasha - Pool 4MN12.020.05 ft, Apr 19, 19657
Winfield Lock and Dam 25MO26.039.62 ft, Aug 1, 19939
Winona - Pool 6MN13.020.77 ft, Apr 19, 19655
Lock and Dam 10 - GuttenbergIA15.023.65 ft, Apr 24, 19652
Lock and Dam 2 - HastingsMN15.025.90 ft, Apr 17, 196512
Lock and Dam 3 - Red WingMN680.5687.77 ft, Apr 19, 19658
Lock and Dam 4 - AlmaWI16.019.78 ft, Apr 19, 19652
Lock and Dam 5 - Minnesota CityMN660.0667.85 ft, Apr 19, 19654
Lock and Dam 5a - WinonaMN655.0663.35 ft, Apr 19, 19654
Lock and Dam 6 - TrempealeauMN647.0653.02 ft, Apr 21, 19654
Lock and Dam 7 - La CrescentMN641.0647.38 ft, Apr 21, 19652
Lock and Dam 8 - GenoaWI631.0638.40 ft, Apr 22, 19653
Lock and Dam 9 - LynxvilleWI625.0633.16 ft, Apr 24, 19653
AitkinMN13.022.49 ft, May 20, 195011
Arkansas CityAR37.059.20 ft, Apr 21, 192715
GreenvilleAR48.065.40 ft, Apr 21, 192718

Other gauges in Madison County

Flood gauges in Madison County
Mel Price (Alton) Lock and Dam21.042.72 ft, Aug 1, 19938

Madison County: every hazard · River floods across the country · Illinois

NOAA National Water Prediction Service, gauge ALOI2, 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.