USGS Streamgage 06605850
Little Sioux River at Linn Grove, IA
Little Sioux River at Linn Grove, IA is USGS streamgage 06605850 in Iowa, monitoring river discharge in hydrologic subbasin 10230003. It sits on the Little Sioux River, alongside 2 other gauges Rivermatics tracks on the same river. It drains a watershed of about 1,548 square miles. Discharge records at this site go back to 1953. Typical flow runs near 549.6 cfs in July and 1,239.3 cfs in April, with the higher of the two arriving in April. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.
View live conditions & forecast →
Gauge details
- State
- Iowa
- Drainage area
- 1,548 sq mi
- Gauge elevation
- 1,261 ft
- Subbasin (HUC-8)
- 10230003
- Coordinates
- 42.89631, -95.243
- USGS site number
- 06605850
- Records begin
- 1953-06-10 (73 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Little Sioux River at Linn Grove, IA. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.
| Date | Low p10 | Expected p50 | High p90 | Range |
|---|---|---|---|---|
| 203 | 250 | 313 | ||
| 171 | 230 | 329 | ||
| 148 | 207 | 311 | ||
| 133 | 188 | 297 | ||
| 129 | 191 | 420 | ||
| 142 | 260 | 853 | ||
| 176 | 497 | 2,143 | ||
| 250 | 1,068 | 3,955 | ||
| 297 | 1,229 | 4,124 | ||
| 305 | 1,178 | 3,709 | ||
| 284 | 1,001 | 3,107 | ||
| 244 | 824 | 2,654 | ||
| 230 | 717 | 2,220 | ||
| 218 | 616 | 1,825 |
All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 54 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| January | 22.1 | 150.6 | 600.7 | |
| February | 24.3 | 196.6 | 969.1 | |
| March | 102.3 | 661.2 | 2,872.9 | |
| April | 171.7 | 1,239.3 | 3,866.3 | |
| May | 207.7 | 1,195.8 | 3,906.1 | |
| June | 250.5 | 1,102 | 4,407.7 | |
| July | 113.3 | 549.6 | 2,753.9 | |
| August | 58.8 | 225.1 | 1,196.4 | |
| September | 42.4 | 146.4 | 1,222.3 | |
| October | 39.5 | 180.1 | 1,746.8 | |
| November | 42.9 | 236.9 | 1,219.7 | |
| December | 29.6 | 190.1 | 853.6 |
All values in cubic feet per second (cfs).
Common questions
- When does Little Sioux River at Linn Grove, IA normally run highest?
- April, on the long-term record. The median daily flow that month is about 1,239.3 cfs, against 146.4 cfs in September, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Little Sioux River at Linn Grove, IA?
- It depends on the month. In January, half of days historically fall near 150.6 cfs, with the middle 80% of days between 22.1 and 600.7 cfs. The month-by-month table on this page gives the full range.
- How long has Little Sioux River at Linn Grove, IA been measured?
- Discharge records at USGS site 06605850 begin in 1953, about 73 years, covering roughly 9,198 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for Little Sioux River at Linn Grove, IA?
- Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
- Where is Little Sioux River at Linn Grove, IA?
- The gauge sits at 42.89631, -95.243, in Iowa, in hydrologic subbasin 10230003, at an elevation of about 1,261 feet, draining roughly 1,548 square miles.
- Can I use Little Sioux River at Linn Grove, IA data for flood or safety decisions?
- No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.
Upstream and downstream on the Little Sioux River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Little Sioux River in full.
- Little Sioux River at Linn Grove, IA this page
- Little Sioux River at Correctionville, IA 2,500 sq mi
- Little Sioux River near Turin, IA 3,526 sq mi