Streamflow
Near normalSnake River above Jackson Lake streamflow
Daily mean discharge, Snake-Columbia basin, Wyoming
Data through Sep 30, 2026 · source last checked Oct 1, 2026 · page revised Oct 1, 2026
Cite
- Discharge
About this data
- Source
- US Geological Survey (USGS)
- Series
- Daily mean streamflow (discharge)
- Geography
- Snake River above Jackson Lake
- Unit
- cfs
- Calculation
- Daily mean
- Last observation
- Sep 30, 2026
- Update frequency
- Daily
Now 230 cfs, 2% below the 5-yr median.
The gauge read 230 cfs, 2% below the 5-yr median. Flow dropped 6.9% on the week and 10.9% on the month. Year over year it was 32.2% higher.
| Period | Current | Prior | Change |
|---|---|---|---|
| Week over week | 230 cfs | 247 cfs | -6.9% |
| Month over month | 230 cfs | 258 cfs | -10.9% |
| Year over year | 230 cfs | 174 cfs | +32.2% |
| vs 5-yr median | 230 cfs | 235 cfs | -2.1% |
| Reading | Discharge |
|---|---|
| Lowest on record for this week | 163 cfs |
| Median for this week | 235 cfs |
| Highest on record for this week | 452 cfs |
Previous weeks
Week of Sep 23, 2026
The Snake River above Jackson Lake ran at 247 cfs, up 21.1% on the week. Flow is 7% below the 5-year median. Year-over-year, the river is running 17.6% higher.
Week of Sep 15, 2026
Discharge reads 206 cfs, down 33 cfs on the week and 16% below the 5-year median. Year over year, the gauge is up 34 cfs from 172 cfs.
Week of Sep 2, 2026
Snake River above Jackson Lake flows at 246 cfs, down 20.9% from a month ago. The gauge reads 10% above the 5-year median and is up 39% year over year.
Week of Aug 26, 2026
Snake River above Jackson Lake streamflow fell to 238 cfs, down 10.9% on the week and 38.2% in the month. Compared to a year ago, flow is 52.6% higher. The gauge sits 8% below its 5-year median.
About Snake River above Jackson Lake
USGS gage 13010065 measures the Snake River above Jackson Lake in northwestern Wyoming, inside Grand Teton National Park and upstream of Jackson Lake Dam. It reads the Snake's headwaters off the Yellowstone plateau and the Teton Wilderness before any storage or diversion touches them, which makes it one of the few genuinely unregulated index gages in the upper Snake system.
The year here is a high-elevation snowmelt year and a pronounced one: very low, stable winter baseflow under ice, a steep rise beginning in May, a June peak, then a long recession. Because everything it measures is captured immediately downstream in Jackson Lake, which Reclamation operates for Idaho irrigators rather than for Wyoming, this gage is effectively the supply forecast for the upper Snake. A weak peak here is the earliest clean signal that the irrigation season downstream in the Snake River Plain will be a short one.