2 USGS Streamgages · Klamath River system
Shasta River flows and levels
Shasta River is gauged at 2 USGS streamgages in California, each tracked by Rivermatics. The mainstem runs about 55 miles (89 km) from headwaters to outlet. It drains into the Klamath River system. Drainage area at the gauges ranges from 673 square miles at Shasta River near Montague, CA up to 793 at Shasta River near Yreka, CA. The gauged reach falls about 430 feet, from 2,467 feet down to 2,037. 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.
| Gauge | State | Drainage sq mi | Elevation ft | April p50 cfs | July p50 cfs | Forecast |
|---|---|---|---|---|---|---|
| Shasta River near Montague, CA | CA | 673 | 2,467 | 104.5 | 28.2 | 14-day |
| Shasta River near Yreka, CA | CA | 793 | 2,037 | 144.2 | 30.9 | 14-day |
Typical flow by month at Shasta River near Yreka, 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 93 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 | 158.2 | 216.8 | 562.5 | |
| February | 162.3 | 238.2 | 615.7 | |
| March | 141.7 | 232.6 | 531.2 | |
| April | 55.8 | 144.2 | 393.5 | |
| May | 35.6 | 105.5 | 268.6 | |
| June | 23 | 69.6 | 190.9 | |
| July | 12.5 | 30.9 | 94.9 | |
| August | 12.8 | 31 | 74.8 | |
| September | 29.2 | 65.2 | 111.7 | |
| October | 103.9 | 143.3 | 188.2 | |
| November | 133.1 | 177.9 | 244 | |
| December | 143.9 | 195.8 | 409.2 |
All values in cubic feet per second (cfs).
Common questions
- When does the Shasta River run highest?
- February, on the long-term record at Shasta River near Yreka, CA — the furthest-downstream gauge Rivermatics tracks on this river. Median daily flow there is about 238.2 cfs that month, against 30.9 cfs in July, 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 Shasta River?
- Rivermatics tracks 2 USGS streamgages on the Shasta 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 Shasta River?
- Yes, at 2 of the 2 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 Shasta River part of?
- The Shasta 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 Shasta 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
- Trinity River 4 gauges
- Lost River 2 gauges
- Scott River 2 gauges