USGS Streamgage 09471000
San Pedro River at Charleston, AZ
San Pedro River at Charleston, AZ is USGS streamgage 09471000 in Arizona, monitoring river discharge in hydrologic subbasin 15050202. It drains a watershed of about 1,234 square miles. Discharge records at this site go back to 1904. Typical flow runs near 23.1 cfs in July and 10 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Arizona
- Drainage area
- 1,234 sq mi
- Gauge elevation
- 3,957 ft
- Subbasin (HUC-8)
- 15050202
- Coordinates
- 31.62594, -110.1751
- USGS site number
- 09471000
- Records begin
- 1904-03-29 (122 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 123 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 | 8.2 | 15.3 | 39.5 | |
| February | 8.8 | 14.5 | 42.2 | |
| March | 8.8 | 14 | 34.9 | |
| April | 5.8 | 10 | 19.2 | |
| May | 3.1 | 6.1 | 11.5 | |
| June | 1.1 | 3 | 12.6 | |
| July | 1.8 | 23.1 | 296.7 | |
| August | 5.3 | 47 | 502.7 | |
| September | 3.3 | 14.7 | 122.5 | |
| October | 2.7 | 7 | 34.3 | |
| November | 5.1 | 10.6 | 24.9 | |
| December | 6.9 | 13.8 | 31.7 |
All values in cubic feet per second (cfs).
Common questions
- When does San Pedro River at Charleston, AZ normally run highest?
- August, on the long-term record. The median daily flow that month is about 47 cfs, against 3 cfs in June, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for San Pedro River at Charleston, AZ?
- It depends on the month. In January, half of days historically fall near 15.3 cfs, with the middle 80% of days between 8.2 and 39.5 cfs. The month-by-month table on this page gives the full range.
- How long has San Pedro River at Charleston, AZ been measured?
- Discharge records at USGS site 09471000 begin in 1904, about 122 years, covering roughly 9,126 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is San Pedro River at Charleston, AZ?
- The gauge sits at 31.62594, -110.1751, in Arizona, in hydrologic subbasin 15050202, at an elevation of about 3,957 feet, draining roughly 1,234 square miles.
- Can I use San Pedro River at Charleston, AZ 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.