Rivermatics

4 USGS Streamgages · Klamath River system

Trinity River flows and levels

Trinity River is gauged at 4 USGS streamgages in California, each tracked by Rivermatics. The mainstem runs about 167 miles (268 km) from headwaters to outlet. It drains into the Klamath River system. Drainage area at the gauges ranges from 149 square miles at Trinity River Ab Coffee C near Trinity Center, CA up to 1,439 at Trinity River near Burnt Ranch, CA. The gauged reach falls about 1,593 feet, from 2,540 feet down to 948. Rivermatics issues a daily machine-learned 14-day flow outlook for every one of them.

Gauges on this river, upstream to downstream

Ordered by drainage area, which is how far down the river each gauge sits. April and July figures are long-term median daily flows for that month from the USGS record — historical normals, not a forecast and not today's reading.

USGS streamgages on this river, ordered upstream to downstream
Gauge State Drainage sq mi Elevation ft April p50 cfs July p50 cfs Forecast
Trinity River Ab Coffee C near Trinity Center, CA CA 149 2,540 767.5 78.7 14-day
Trinity River below Limekiln Gulch near Douglas City, CA CA 810 1,665 664.2 532.1 14-day
Trinity River Ab NF Trinity River near Helena, CA CA 1,137 1,357 1,479.7 742.3 14-day + temp
Trinity River near Burnt Ranch, CA CA 1,439 948 2,101.7 700.5 14-day

Typical flow by month at Trinity River near Burnt Ranch, CA

The furthest-downstream gauge on this river, so the fullest flow it carries here. 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 645.3 1,773.9 7,261.6
February 836.2 2,029.3 7,589
March 1,036.4 2,263.5 6,318.1
April 1,040.4 2,101.7 5,501.7
May 1,053.1 2,401.9 6,180
June 713.2 1,300.9 3,759
July 404.5 700.5 1,691.5
August 265.7 537.7 902.7
September 278.6 526.5 876.6
October 325.7 479.3 727.5
November 410.2 581.7 1,935.2
December 499.4 1,026.6 4,654.5

All values in cubic feet per second (cfs).

Common questions

When does the Trinity River run highest?
May, on the long-term record at Trinity River near Burnt Ranch, CA — the furthest-downstream gauge Rivermatics tracks on this river. Median daily flow there is about 2,401.9 cfs that month, against 479.3 cfs in October, the lowest. Upstream gauges peak on their own schedule; the table on this page gives April and July for each.
How many gauges are on the Trinity River?
Rivermatics tracks 4 USGS streamgages on the Trinity River, across California. Each has its own page with the site's full flow record and monthly normals. The river may carry other gauges that publish neither daily values nor discharge statistics; those are not tracked here.
Is there a flow forecast for the Trinity River?
Yes, at 4 of the 4 gauges. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on each basin's observed flows, weather and snowpack, and issues a daily 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 each gauge's live screen.
What river system is the Trinity River part of?
The Trinity River drains into the Klamath River system — it is a tributary somewhere in that chain, following the flowpath down to its terminal river. Rivermatics builds this from the USGS/geoconnex reference-mainstem network rather than from names.
Can I use Trinity River 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.

Other rivers in the Klamath River system

Browse nearby gauges by state