4 USGS Streamgages · Santa Ana River system
San Jacinto River flows and levels
San Jacinto River is gauged at 4 USGS streamgages in California, each tracked by Rivermatics. It feeds the Temescal Wash. It drains into the Santa Ana River system. Drainage area at the gauges ranges from 142 square miles at San Jacinto River near San Jacinto up to 723 at San Jacinto River near Elsinore, CA. The gauged reach falls about 658 feet, from 1,925 feet down to 1,267. Rivermatics issues a daily machine-learned 14-day flow outlook at 3 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 |
|---|---|---|---|---|---|---|
| San Jacinto River near San Jacinto | CA | 142 | 1,925 | 10 | 0 | 14-day |
| San Jacinto River Ab State Street near San Jacinto, CA | CA | 252 | 1,492 | 0 | 0 | — |
| San Jacinto River near Sun City, CA | CA | 560 | 1,398 | 0 | 0 | 14-day |
| San Jacinto River near Elsinore, CA | CA | 723 | 1,267 | 0.7 | 0 | 14-day |
Typical flow by month at San Jacinto River near Elsinore, 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 111 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 | 0 | 0.8 | 14.4 | |
| February | 0 | 1.1 | 109.6 | |
| March | 0 | 1.1 | 194.4 | |
| April | 0 | 0.7 | 60.9 | |
| May | 0 | 0.3 | 7.1 | |
| June | 0 | 0 | 1.4 | |
| July | 0 | 0 | 0.8 | |
| August | 0 | 0 | 0.6 | |
| September | 0 | 0 | 0.5 | |
| October | 0 | 0 | 0.7 | |
| November | 0 | 0.2 | 1.2 | |
| December | 0 | 0.5 | 2.8 |
All values in cubic feet per second (cfs).
Common questions
- When does the San Jacinto River run highest?
- February, on the long-term record at San Jacinto River near Elsinore, CA — the furthest-downstream gauge Rivermatics tracks on this river. Median daily flow there is about 1.1 cfs that month, against 0 cfs in June, 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 San Jacinto River?
- Rivermatics tracks 4 USGS streamgages on the San Jacinto 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 San Jacinto River?
- Yes, at 3 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 San Jacinto River part of?
- The San Jacinto River drains into the Santa Ana 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 San Jacinto 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.