Rock River in Illinois
Around here
Around Rock River
Camping2
Public land: USGS PAD-US
About this river
Rock River is a 35.7 mile river. Streamflow is measured at the USGS gauge Rock River at Byron, IL (site 05440700). The National Hydrography Dataset places it at stream order 8. Reach geometry comes from the USGS National Hydrography Dataset.
Typical flow by month
2000 to 2026
Rock River typically runs highest in April, at a median 10,450 cfs, and lowest in September, at 4,220 cfs. The highest flow on record for any single day is 39,600 cfs, in 2013.
Show the numbers
| Month | Typical (cfs) | Usual range (cfs) |
|---|---|---|
| January | 4,800 | 3,700 to 7,950 |
| February | 5,660 | 3,550 to 8,520 |
| March | 9,880 | 7,100 to 13,500 |
| April | 10,450 | 7,405 to 13,200 |
| May | 8,630 | 6,350 to 12,000 |
| June | 8,165 | 5,090 to 12,050 |
| July | 5,980 | 3,570 to 9,140 |
| August | 4,670 | 3,190 to 6,740 |
| September | 4,220 | 2,975 to 6,575 |
| October | 4,340 | 3,260 to 5,810 |
| November | 5,185 | 3,665 to 6,680 |
| December | 4,880 | 3,720 to 7,390 |
Typical is the median of each month’s daily median values, and the usual range runs from the median 25th to the median 75th percentile, across about 26 years of record. Statistics published by the US Geological Survey for Rock River at Byron, IL (site 05440700). Conditions on any given day can fall well outside the usual range. Check the current reading before you go.
Boat access nearby
8 mapped launches sit in the mapped area of Rock River, all of them public access. Ramp data comes from the USGS national boat-ramp inventory.
Embed this gauge on your site
Paste this snippet anywhere, an outfitter page, a club site, a trip report, to show Rock River's live streamflow, water level and 7-day trend. It reads the USGS gauge directly, updates itself, and links back here.
See every free widget you can put on your site, including live conditions and a 7 day forecast.
