USGS Streamgage 08374550
Rio Grande near Castolon, TX
Rio Grande near Castolon, TX is USGS streamgage 08374550 in Texas, monitoring river discharge in hydrologic subbasin 13040205. Discharge records at this site go back to 2007. Typical flow runs near 227.4 cfs in July and 47.9 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Texas
- Gauge elevation
- 2,110 ft
- Subbasin (HUC-8)
- 13040205
- Coordinates
- 29.13798, -103.5249
- USGS site number
- 08374550
- Records begin
- 2007-08-03 (19 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 19 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 | 19.8 | 178.6 | 402.8 | |
| February | 9.9 | 124.3 | 328.2 | |
| March | 6.2 | 71 | 269.4 | |
| April | 1.5 | 47.9 | 237.4 | |
| May | 0.5 | 49.7 | 1,031.3 | |
| June | 5.8 | 100.7 | 1,429.7 | |
| July | 20.7 | 227.4 | 2,073.5 | |
| August | 26.4 | 319.9 | 4,582.6 | |
| September | 60.3 | 673.1 | 7,738.7 | |
| October | 20.8 | 586.8 | 2,989.2 | |
| November | 7.3 | 310.1 | 945 | |
| December | 11.6 | 239.7 | 613.8 |
All values in cubic feet per second (cfs).
Common questions
- When does Rio Grande near Castolon, TX normally run highest?
- September, on the long-term record. The median daily flow that month is about 673.1 cfs, against 47.9 cfs in April, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Rio Grande near Castolon, TX?
- It depends on the month. In January, half of days historically fall near 178.6 cfs, with the middle 80% of days between 19.8 and 402.8 cfs. The month-by-month table on this page gives the full range.
- How long has Rio Grande near Castolon, TX been measured?
- Discharge records at USGS site 08374550 begin in 2007, about 19 years, covering roughly 6,938 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Rio Grande near Castolon, TX?
- The gauge sits at 29.13798, -103.5249, in Texas, in hydrologic subbasin 13040205, at an elevation of about 2,110 feet.
- Can I use Rio Grande near Castolon, TX 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.