Colorado River (Upper)
The best month to fish the Colorado River (Upper) is August. The month to avoid is June. Right now, in September, it is worth going.
- January: 71 out of 100
- February: 71 out of 100
- March: 71 out of 100
- April: 83 out of 100
- May: 56 out of 100
- June: 52 out of 100
- July: 81 out of 100
- August: 98 out of 100
- September: 98 out of 100
- October: 71 out of 100
- November: 71 out of 100
- December: 71 out of 100
- The water is 7°F warmer than normal for this month — 63°F right now against a typical 56°F.
LIVE FROM USGS GAUGE 09058000 · EVERYTHING ELSE ON THIS PAGE IS A TWENTY-YEAR NORMAL
GAUGE 09058000 · COLOURED BY SEPTEMBER
Month by month
| MONTH | TYPICAL FLOW | RANGE (P20–P80) | WATER | AIR HIGH | RAIN | SCORE |
|---|---|---|---|---|---|---|
| January | 420 cfs | 387–509 | — | — | — | 71 |
| February | 447 cfs | 389–495 | — | — | — | 71 |
| March | 502 cfs | 425–634 | — | — | — | 71 |
| April | 859 cfs | 758–1,044 | 44.1°F | — | — | 83 |
| May | 1,606 cfs | 843–2,562 | 50.4°F | — | — | 56 |
| June | 2,870 cfs | 837–3,847 | 55.5°F | — | — | 52 |
| July | 1,298 cfs | 978–2,173 | 59.5°F | — | — | 81 |
| August | 1,120 cfs | 1,026–1,261 | 58.4°F | — | — | 98 |
| SeptemberNOW | 1,103 cfs | 970–1,231 | 56.1°F | — | — | 98 |
| October | 945 cfs | 696–1,101 | — | — | — | 71 |
| November | 526 cfs | 487–586 | — | — | — | 71 |
| December | 426 cfs | 386–485 | — | — | — | 71 |
WHERE THESE NUMBERS COME FROM
Flow and water temperature are medians of the monthly means reported by USGS gauge 09058000 over 2006-2025. Air temperature and precipitation are ten-year normals from Open-Meteo at this river’s gauge coordinates.
The window is deliberate. USGS’s own full-record statistics for a dammed river reach back before the dam — at Lees Ferry, to 1922, forty-one years before Glen Canyon closed — and describe a river that no longer exists.
Flow is scored against this river’s own fishable band of 502–1,120 cfs. There is no universal band: 8,000 cfs is low water on a big tailwater and a flood on a spring creek.
Water temperature is a ceiling rather than a weight. Above about 68°F a trout that is fought and released frequently dies anyway, so no month above that line is scored as worth booking, however good its flow.
The Colorado River (Upper) is at its best in August — water around 58°F, flows near 1,120 cfs.
← RIVERS GOING WELL IN SEPTEMBERRegulations, licences and access change without notice and are not reproduced here as fact — check the state agency before you travel. A median describes twenty years; it does not forecast your week. Source: U.S. Geological Survey, National Water Information System.