USGS Streamgage 11446500
American River A Fair Oaks, CA
American River A Fair Oaks, CA is USGS streamgage 11446500 in California, monitoring river discharge in hydrologic subbasin 18020111. It drains a watershed of about 1,888 square miles. Discharge records at this site go back to 1862. Typical flow runs near 3,561 cfs in July and 2,888 cfs in April, with the higher of the two arriving in July. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.
View live conditions & forecast →
Gauge details
- State
- California
- Drainage area
- 1,888 sq mi
- Gauge elevation
- 74 ft
- Subbasin (HUC-8)
- 18020111
- Coordinates
- 38.63544, -121.22769
- USGS site number
- 11446500
- Records begin
- 1862-01-10 (164 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for American River A Fair Oaks, CA. 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 |
|---|---|---|---|---|
| 1,623 | 1,838 | 2,002 | ||
| 1,517 | 1,784 | 2,059 | ||
| 1,435 | 1,748 | 2,134 | ||
| 1,379 | 1,729 | 2,201 | ||
| 1,352 | 1,725 | 2,246 | ||
| 1,328 | 1,720 | 2,284 | ||
| 1,324 | 1,729 | 2,332 | ||
| 1,316 | 1,735 | 2,363 | ||
| 1,313 | 1,743 | 2,419 | ||
| 1,275 | 1,712 | 2,351 | ||
| 1,280 | 1,714 | 2,289 | ||
| 1,278 | 1,714 | 2,349 | ||
| 1,268 | 1,710 | 2,390 | ||
| 1,268 | 1,718 | 2,430 |
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 71 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 | 708.4 | 1,981 | 11,749.4 | |
| February | 853.6 | 2,719.3 | 10,959.3 | |
| March | 889.2 | 3,255.5 | 11,304.5 | |
| April | 996.8 | 2,888 | 9,047.3 | |
| May | 992.3 | 3,190.3 | 9,171.9 | |
| June | 1,654 | 3,206.7 | 7,513.7 | |
| July | 1,989.7 | 3,561 | 5,099 | |
| August | 1,416.8 | 2,749 | 4,001.6 | |
| September | 971.6 | 1,972.3 | 3,568.7 | |
| October | 626.5 | 1,655.8 | 2,959 | |
| November | 637.2 | 1,832.3 | 3,484 | |
| December | 676 | 2,008.7 | 7,138.4 |
All values in cubic feet per second (cfs).
Common questions
- When does American River A Fair Oaks, CA normally run highest?
- July, on the long-term record. The median daily flow that month is about 3,561 cfs, against 1,655.8 cfs in October, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for American River A Fair Oaks, CA?
- It depends on the month. In January, half of days historically fall near 1,981 cfs, with the middle 80% of days between 708.4 and 11,749.4 cfs. The month-by-month table on this page gives the full range.
- How long has American River A Fair Oaks, CA been measured?
- Discharge records at USGS site 11446500 begin in 1862, about 164 years, covering roughly 9,130 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for American River A Fair Oaks, CA?
- 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 American River A Fair Oaks, CA?
- The gauge sits at 38.63544, -121.22769, in California, in hydrologic subbasin 18020111, at an elevation of about 74 feet, draining roughly 1,888 square miles.
- Can I use American River A Fair Oaks, CA 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.