River stage
Alton, Mississippi River
- River level
- 18.62 ft
- Status
- Below flood stage
- 7-day change
- +3.16 ft
- Recent high
- 19.66 ft
- Recent low
- 14.37 ft
Last reported 2026-10-13 | NWS ALOI2
- 30-day change
- -0.84 ft
- Average
- 17.30 ft
- Readings
- 122
- Data span
- 122 days
- Record crest
- 39.55 ft
In brief
The Mississippi River at Alton, IL read 18.62 ft on Oct 13, 2026, 1.38 ft below action stage. That is 0.84 ft lower than 30 days earlier.
Source: National Weather Service gauge ALOI2
Water 68 °F (20 °C)
River level timeline
Stage threshold profile
Highest crests on record
| Rank | Crest | Date |
|---|---|---|
| 1 | 39.55 ft | 1993-08-01 |
| 2 | 35.30 ft | 2019-06-09 |
| 3 | 31.94 ft | 2016-01-01 |
| 4 | 31.60 ft | 2019-05-07 |
| 5 | 31.43 ft | 1995-05-22 |
| 6 | 31.27 ft | 2013-06-04 |
| 7 | 31.02 ft | 2017-05-06 |
| 8 | 29.78 ft | 2008-06-29 |
Flood crests recorded at this gauge by the National Weather Service.
What happens at each level
- 19.70 ft
During open river conditions (Mel Price gates are open), Dresser Island Drive begins flooding near this level.
- 20.70 ft
During open river conditions (Mel Price gates all open), Alta Villa Road off of Highway 94 begins flooding and is closed.
- 21.70 ft
At this level, Highway 94 and the east end of Harbor Point Road off of Missouri Highway 94 north of West Alton begin flooding. Also, the access road the Lincoln Shields recreation area off of U.S. Highway 367 just west of the Clark bridge begins flooding.
- 22.20 ft
Missouri Highway 94 between Portage Des Sioux and West Alton begins flooding. Yachtview Drive begins flooding along the entrance to Harbor Point Yacht Club.
- 23.20 ft
Yachtview Drive begins flooding along the entrance to Harbor Point Yacht Club near this height.
- 23.30 ft
Near this height, the outer road between Riverlands Way and the Lincoln Shields Access Road will close due to flooding.
- 24.20 ft
The Wood River South Levee flood gate is closed near this height.
- 24.50 ft
Highway 100 begins flooding at the Clifton Terrace Street intersection near this height.
- 24.60 ft
Missouri Highway 94 from Alta Villa Road to Feltes Drive will be closed near this height.
- 25.50 ft
Highway 100 will begin flooding at Clifton Terrace Street within 2 feet of this height.
Written by the local National Weather Service forecast office for this exact gauge.
Frequently asked questions
Is the Mississippi River flooding at Alton?
No. The Mississippi River at Alton is at 18.62 ft, 1.38 ft below action stage.
What is the flood stage at Alton?
The National Weather Service sets action stage 20 ft, minor flooding 21 ft, moderate flooding 24 ft and major flooding 31 ft.
What is the highest the Mississippi River has been at Alton?
The highest crest on record is 39.55 ft, on 1993-08-01.
Is the Mississippi River high or low right now at Alton?
At 18.62 ft it is higher than 62% of readings over the last 122 days.
How warm is the water at Alton, Mississippi River?
The water temperature at Alton, Mississippi River is 68 °F (20.3 °C), measured 7:00 pm by USGS. It has held steady over the last 24 hours.
Stage and flood information from the NOAA National Weather Service (gauge ALOI2); daily history from the U.S. Geological Survey (site 05587498). Last reading 2026-10-13. For flood safety decisions always follow official National Weather Service warnings.