USGS Streamgage 11189500
SF Kern River near Onyx, CA
SF Kern River near Onyx, CA is USGS streamgage 11189500 in California, monitoring river discharge in hydrologic subbasin 18030002. It drains a watershed of about 530 square miles. Discharge records at this site go back to 1911. Typical flow runs near 20.5 cfs in July and 230.5 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 530 sq mi
- Gauge elevation
- 2,854 ft
- Subbasin (HUC-8)
- 18030002
- Coordinates
- 35.73747, -118.17369
- USGS site number
- 11189500
- Records begin
- 1911-09-12 (115 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 115 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 | 19 | 40.7 | 122.9 | |
| February | 28.6 | 58.5 | 185.4 | |
| March | 43.6 | 108.4 | 356.7 | |
| April | 50.6 | 230.5 | 841.7 | |
| May | 24.5 | 170.6 | 1,237.1 | |
| June | 7.3 | 65.7 | 501.5 | |
| July | 1.4 | 20.5 | 148 | |
| August | 0.9 | 10.2 | 62.8 | |
| September | 1.2 | 11.4 | 42.1 | |
| October | 5.8 | 18.9 | 47.3 | |
| November | 11.5 | 27.6 | 61 | |
| December | 15 | 31.7 | 79 |
All values in cubic feet per second (cfs).
Common questions
- When does SF Kern River near Onyx, CA normally run highest?
- April, on the long-term record. The median daily flow that month is about 230.5 cfs, against 10.2 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 SF Kern River near Onyx, CA?
- It depends on the month. In January, half of days historically fall near 40.7 cfs, with the middle 80% of days between 19 and 122.9 cfs. The month-by-month table on this page gives the full range.
- How long has SF Kern River near Onyx, CA been measured?
- Discharge records at USGS site 11189500 begin in 1911, about 115 years, covering roughly 9,125 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is SF Kern River near Onyx, CA?
- The gauge sits at 35.73747, -118.17369, in California, in hydrologic subbasin 18030002, at an elevation of about 2,854 feet, draining roughly 530 square miles.
- Can I use SF Kern River near Onyx, CA 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.