USGS Streamgage 09402500
Colorado River near Grand Canyon, AZ
Colorado River near Grand Canyon, AZ is USGS streamgage 09402500 in Arizona, monitoring river discharge in hydrologic subbasin 15010001. It drains a watershed of about 141,600 square miles. Discharge records at this site go back to 1884. Typical flow runs near 15,564.5 cfs in July and 12,493.3 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Arizona
- Drainage area
- 141,600 sq mi
- Gauge elevation
- 2,419 ft
- Subbasin (HUC-8)
- 15010001
- Coordinates
- 36.10137, -112.08628
- USGS site number
- 09402500
- Records begin
- 1884-01-01 (142 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 104 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 | 4,459 | 10,510 | 17,329 | |
| February | 5,497.2 | 9,978.3 | 17,441.4 | |
| March | 6,238.7 | 10,602.9 | 17,029 | |
| April | 8,060.7 | 12,493.3 | 29,846.7 | |
| May | 9,158.7 | 16,529 | 58,922.6 | |
| June | 9,777 | 17,803.3 | 69,256.7 | |
| July | 8,157.7 | 15,564.5 | 32,080.6 | |
| August | 5,631.9 | 14,177.4 | 22,683.9 | |
| September | 4,231.7 | 10,614.7 | 19,933.3 | |
| October | 5,096.8 | 9,087.4 | 16,600 | |
| November | 5,779.3 | 9,047.7 | 16,443.3 | |
| December | 4,898.7 | 9,623.2 | 16,812.9 |
All values in cubic feet per second (cfs).
Common questions
- When does Colorado River near Grand Canyon, AZ normally run highest?
- June, on the long-term record. The median daily flow that month is about 17,803.3 cfs, against 9,047.7 cfs in November, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Colorado River near Grand Canyon, AZ?
- It depends on the month. In January, half of days historically fall near 10,510 cfs, with the middle 80% of days between 4,459 and 17,329 cfs. The month-by-month table on this page gives the full range.
- How long has Colorado River near Grand Canyon, AZ been measured?
- Discharge records at USGS site 09402500 begin in 1884, about 142 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 Colorado River near Grand Canyon, AZ?
- The gauge sits at 36.10137, -112.08628, in Arizona, in hydrologic subbasin 15010001, at an elevation of about 2,419 feet, draining roughly 141,600 square miles.
- Can I use Colorado River near Grand Canyon, 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.