Ohio River at Olmsted, IL: flow right now vs. normal
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—flow right now
—of typical for this month
—gage height
The Ohio River at Olmsted, IL gauge has averaged 324,384 cfs over 12 years of monthly records. Flow is usually highest in March (642,833 cfs) and lowest in October (128,400 cfs).
Typical flow by month
Highest in March (642,833 cfs), lowest in October (128,400 cfs).
Key figures
- Average flow
- 324,384 cfs
- Highest peak on record
- 1,290,000 cfs
- Year of that peak
- 2019
- Drainage area
- 203,000 sq mi
- Years of records
- 12
- Gauge elevation
- 278 ft
- River
- Ohio River
- County
- Pulaski
- State
- Illinois
Monthly numbers
| Month | Average | Median | Lowest | Highest |
|---|---|---|---|---|
| Jan | 481,000 cfs | 433,000 cfs | 298,000 cfs | 824,000 cfs |
| Feb | 556,864 cfs | 471,000 cfs | 264,000 cfs | 1,020,000 cfs |
| Mar | 642,833 cfs | 691,000 cfs | 314,000 cfs | 1,030,000 cfs |
| Apr | 485,667 cfs | 456,750 cfs | 219,500 cfs | 763,500 cfs |
| May | 377,250 cfs | 355,000 cfs | 147,000 cfs | 644,000 cfs |
| Jun | 205,333 cfs | 192,000 cfs | 94,500 cfs | 332,500 cfs |
| Jul | 224,750 cfs | 182,000 cfs | 112,000 cfs | 509,000 cfs |
| Aug | 140,558 cfs | 139,000 cfs | 93,700 cfs | 183,000 cfs |
| Sep | 129,621 cfs | 105,450 cfs | 67,000 cfs | 353,500 cfs |
| Oct | 128,400 cfs | 115,000 cfs | 61,100 cfs | 264,000 cfs |
| Nov | 207,127 cfs | 183,500 cfs | 84,250 cfs | 595,500 cfs |
| Dec | 325,127 cfs | 273,000 cfs | 97,400 cfs | 617,000 cfs |
Monthly averages of daily flow over the gauge's record. Lowest and highest are the extreme monthly averages for that month.
How Ohio River at Olmsted, IL compares in Illinois
- Ohio River at Olmsted, IL ranks #1 of 189 gauges in Illinois in this dataset by average flow.
- That places it in the top 1% in Illinois by average flow.
- The median average flow of gauges in Illinois is 99.5 cfs.
- Among all 2,293 gauges in the dataset, Ohio River at Olmsted, IL ranks #1 by average flow.
Data: U.S. Geological Survey (USGS) (public domain, U.S. federal data).· Updated 2026-11-02 · Text generated from the data and checked against it.
Live values are provisional USGS data. Measurements only, not a safety assessment — for flood warnings see the National Weather Service. Official page: USGS 03612600.