USGS Streamgage 12155300
Pilchuck River near Snohomish, WA
Pilchuck River near Snohomish, WA is USGS streamgage 12155300 in Washington, monitoring river discharge in hydrologic subbasin 17110011. It drains a watershed of about 127 square miles. Discharge records at this site go back to 1992. Typical flow runs near 110.8 cfs in July and 489.8 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.
View live conditions & forecast →
Gauge details
- State
- Washington
- Drainage area
- 127 sq mi
- Gauge elevation
- 52 ft
- Subbasin (HUC-8)
- 17110011
- Coordinates
- 47.93482, -122.07318
- USGS site number
- 12155300
- Records begin
- 1992-05-05 (34 years)
- Rivermatics forecast
- 14-day flow outlook
14-day flow forecast
Based on observations through for Pilchuck River near Snohomish, 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 |
|---|---|---|---|---|
| 45.5 | 47.4 | 49.4 | ||
| 44.9 | 47.2 | 49.8 | ||
| 47.4 | 53.4 | 70.8 | ||
| 48.8 | 56.8 | 84.1 | ||
| 45.8 | 51.8 | 68 | ||
| 43.9 | 48.2 | 56.9 | ||
| 42.6 | 46.5 | 53 | ||
| 41.6 | 45.3 | 50.4 | ||
| 41 | 44.6 | 49.5 | ||
| 40.6 | 44.4 | 49.5 | ||
| 40.2 | 44 | 48.9 | ||
| 39.8 | 43.5 | 48.2 | ||
| 39.1 | 42.9 | 47.4 | ||
| 38.6 | 42.4 | 46.9 |
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 34 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 | 291.7 | 709.6 | 1,921.9 | |
| February | 265 | 561.6 | 1,612.8 | |
| March | 278.8 | 588.7 | 1,439.5 | |
| April | 285.8 | 489.8 | 1,083.9 | |
| May | 155.5 | 319.2 | 792.7 | |
| June | 102.8 | 239.5 | 569.5 | |
| July | 65.9 | 110.8 | 252.1 | |
| August | 48 | 68 | 143.9 | |
| September | 48.1 | 73.1 | 263.8 | |
| October | 72.4 | 184.1 | 785.5 | |
| November | 179.2 | 533.2 | 1,709.7 | |
| December | 272.1 | 620.2 | 1,850 |
All values in cubic feet per second (cfs).
Common questions
- When does Pilchuck River near Snohomish, WA normally run highest?
- January, on the long-term record. The median daily flow that month is about 709.6 cfs, against 68 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 Pilchuck River near Snohomish, WA?
- It depends on the month. In January, half of days historically fall near 709.6 cfs, with the middle 80% of days between 291.7 and 1,921.9 cfs. The month-by-month table on this page gives the full range.
- How long has Pilchuck River near Snohomish, WA been measured?
- Discharge records at USGS site 12155300 begin in 1992, about 34 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 Pilchuck River near Snohomish, 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. 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 Pilchuck River near Snohomish, WA?
- The gauge sits at 47.93482, -122.07318, in Washington, in hydrologic subbasin 17110011, at an elevation of about 52 feet, draining roughly 127 square miles.
- Can I use Pilchuck River near Snohomish, 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.