USGS Streamgage 12137290
South Fork Sultan River near Sultan, WA
South Fork Sultan River near Sultan, WA is USGS streamgage 12137290 in Washington, monitoring river discharge in hydrologic subbasin 17110009. It drains a watershed of about 12 square miles. Discharge records at this site go back to 1990. Typical flow runs near 42.5 cfs in July and 120.8 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, alongside daily high and low water-temperature forecasts.
View live conditions & forecast →
Gauge details
- State
- Washington
- Drainage area
- 12 sq mi
- Gauge elevation
- 1,465 ft
- Subbasin (HUC-8)
- 17110009
- Coordinates
- 47.94733, -121.62678
- USGS site number
- 12137290
- Records begin
- 1990-11-24 (36 years)
- Rivermatics forecast
- 14-day flow outlook + water temperature
14-day flow forecast
Based on observations through for South Fork Sultan River near Sultan, WA. 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 |
|---|---|---|---|---|
| 5.1 | 5.4 | 6 | ||
| 5 | 5.5 | 6.3 | ||
| 6.8 | 13.2 | 39.9 | ||
| 7.1 | 12.4 | 28.6 | ||
| 6 | 8.5 | 15.2 | ||
| 5.4 | 6.9 | 10 | ||
| 4.9 | 6 | 8.1 | ||
| 4.6 | 5.6 | 7.2 | ||
| 4.4 | 5.4 | 6.9 | ||
| 4.4 | 5.2 | 6.6 | ||
| 4.2 | 5.1 | 6.3 | ||
| 4.1 | 4.9 | 6.1 | ||
| 4 | 4.8 | 6 | ||
| 3.9 | 4.7 | 5.8 |
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 35 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 | 35.4 | 103.7 | 494.1 | |
| February | 31.8 | 70.9 | 289.7 | |
| March | 37.4 | 85.3 | 305.5 | |
| April | 61.2 | 120.8 | 289 | |
| May | 73.3 | 155.5 | 330.2 | |
| June | 48.4 | 118.1 | 273.1 | |
| July | 15.6 | 42.5 | 135 | |
| August | 7.5 | 14.6 | 57.6 | |
| September | 7 | 19.5 | 124.6 | |
| October | 14.4 | 70.3 | 359.4 | |
| November | 37.9 | 123 | 551.8 | |
| December | 34.8 | 82.7 | 407.5 |
All values in cubic feet per second (cfs).
Common questions
- When does South Fork Sultan River near Sultan, WA normally run highest?
- May, on the long-term record. The median daily flow that month is about 155.5 cfs, against 14.6 cfs in August, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for South Fork Sultan River near Sultan, WA?
- It depends on the month. In January, half of days historically fall near 103.7 cfs, with the middle 80% of days between 35.4 and 494.1 cfs. The month-by-month table on this page gives the full range.
- How long has South Fork Sultan River near Sultan, WA been measured?
- Discharge records at USGS site 12137290 begin in 1990, about 36 years, covering roughly 9,200 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Is there a flow forecast for South Fork Sultan River near Sultan, WA?
- 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. A companion model forecasts each day's water-temperature high and low. 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 South Fork Sultan River near Sultan, WA?
- The gauge sits at 47.94733, -121.62678, in Washington, in hydrologic subbasin 17110009, at an elevation of about 1,465 feet, draining roughly 12 square miles.
- Can I use South Fork Sultan River near Sultan, WA 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.