Rivermatics

USGS Streamgage 12121600

Issaquah Creek near Mouth near Issaquah, WA

Issaquah Creek near Mouth near Issaquah, WA is USGS streamgage 12121600 in Washington, monitoring river discharge in hydrologic subbasin 17110012. It sits on the Issaquah Creek, alongside 1 other gauge Rivermatics tracks on the same river. It drains a watershed of about 57 square miles. Discharge records at this site go back to 1963. Typical flow runs near 35.5 cfs in July and 136.2 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
57 sq mi
Gauge elevation
52 ft
Subbasin (HUC-8)
17110012
Coordinates
47.5523, -122.04788
USGS site number
12121600
Records begin
1963-10-01 (63 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Issaquah Creek near Mouth near Issaquah, 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.

Forecast daily mean discharge in cubic feet per second, by date
Date Low p10 Expected p50 High p90 Range
18.5 19 19.5
31.8 55.6 127
25 36 57.9
22.1 27.3 36.4
20.4 23.4 28.2
19.3 21.8 25.4
18.5 20.7 24.3
18 20.2 23.4
17.9 20.1 23
17.4 19.6 22.4
17.2 19.3 22
17.9 20.6 25
19.9 25.4 36
21.1 27.4 39

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 63 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 91.8 195.9 528.9
February 88.9 171.1 402.7
March 95.2 168.3 350.2
April 79.3 136.2 250.5
May 52.7 84.8 154.1
June 35.2 58.5 143.5
July 23 35.5 66.6
August 17.6 25.7 45.1
September 18.6 26.6 59
October 24.5 41 110.2
November 43.2 120.6 328.3
December 73.8 180 464.8

All values in cubic feet per second (cfs).

Common questions

When does Issaquah Creek near Mouth near Issaquah, WA normally run highest?
January, on the long-term record. The median daily flow that month is about 195.9 cfs, against 25.7 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 Issaquah Creek near Mouth near Issaquah, WA?
It depends on the month. In January, half of days historically fall near 195.9 cfs, with the middle 80% of days between 91.8 and 528.9 cfs. The month-by-month table on this page gives the full range.
How long has Issaquah Creek near Mouth near Issaquah, WA been measured?
Discharge records at USGS site 12121600 begin in 1963, about 63 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 Issaquah Creek near Mouth near Issaquah, 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 Issaquah Creek near Mouth near Issaquah, WA?
The gauge sits at 47.5523, -122.04788, in Washington, in hydrologic subbasin 17110012, at an elevation of about 52 feet, draining roughly 57 square miles.
Can I use Issaquah Creek near Mouth near Issaquah, 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 Issaquah Creek

Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Issaquah Creek in full.

Other gauges in this subbasin