USGS Streamgage 12155500
Snohomish River at Snohomish, WA
Snohomish River at Snohomish, WA is USGS streamgage 12155500 in Washington, monitoring river discharge in hydrologic subbasin 17110011. It sits on the Snohomish River, alongside 1 other gauge Rivermatics tracks on the same river. It drains a watershed of about 1,714 square miles. Discharge records at this site go back to 1906. Typical flow runs near 12,764.7 cfs in July and 17,220.8 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Washington
- Drainage area
- 1,714 sq mi
- Gauge elevation
- 7 ft
- Subbasin (HUC-8)
- 17110011
- Coordinates
- 47.911, -122.09875
- USGS site number
- 12155500
- Records begin
- 1906-01-01 (120 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 1 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.
Only 9 of 12 months have enough record to summarize; the rest are omitted.
| Month | Low p10 | Typical p50 | High p90 | Range |
|---|---|---|---|---|
| January | — | 20,307.7 | — | |
| March | — | 14,758.8 | — | |
| April | — | 17,220.8 | — | |
| May | — | 17,160 | — | |
| June | — | 15,200 | — | |
| July | — | 12,764.7 | — | |
| October | — | 11,675 | — | |
| November | — | 15,146.2 | — | |
| December | — | 16,572.7 | — |
All values in cubic feet per second (cfs).
Common questions
- When does Snohomish River at Snohomish, WA normally run highest?
- January, on the long-term record. The median daily flow that month is about 20,307.7 cfs, against 11,675 cfs in October, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- How long has Snohomish River at Snohomish, WA been measured?
- Discharge records at USGS site 12155500 begin in 1906, about 120 years, covering roughly 86 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Snohomish River at Snohomish, WA?
- The gauge sits at 47.911, -122.09875, in Washington, in hydrologic subbasin 17110011, at an elevation of about 7 feet, draining roughly 1,714 square miles.
- Can I use Snohomish River at 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.
Upstream and downstream on the Snohomish River
Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Snohomish River in full.
- Snohomish River near Monroe, WA 1,537 sq mi
- Snohomish River at Snohomish, WA this page