Streamflow
Above normalSnake River above Jackson Lake streamflow
Daily mean discharge, Snake-Columbia basin, Wyoming
Data through Oct 15, 2026 · source last checked Oct 17, 2026 · page revised Oct 16, 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
- Oct 15, 2026
- Update frequency
- Daily
Now 284 cfs, 20% above the 5-yr median.
284 cfs on the Snake River above Jackson Lake, up 32.7% on the week and 37.2% on the month. The flow is running 20% above the 5-year median for this period but is down 4.1% year over year.
| Period | Current | Prior | Change |
|---|---|---|---|
| Week over week | 284 cfs | 214 cfs | +32.7% |
| Month over month | 284 cfs | 207 cfs | +37.2% |
| Year over year | 284 cfs | 296 cfs | -4.1% |
| vs 5-yr median | 284 cfs | 236 cfs | +20.3% |
| Reading | Discharge |
|---|---|
| Lowest on record for this week | 191 cfs |
| Median for this week | 236 cfs |
| Highest on record for this week | 369 cfs |
Previous weeks
An earlier week
The Snake River above Jackson Lake ran at 296 cfs, up 37.7% on the week from 215 cfs. The flow sits 25% above the 5-year median.
Week of Oct 7, 2026
Snake River above Jackson Lake measured 214 cfs through October 7, down 7.8% from a week ago but up 1.4% year over year. The flow sits at the 5-year median for this date.
Week of Sep 30, 2026
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.
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.
About Snake River above Jackson Lake
The Snake River above Jackson Lake ran 284 cfs on Oct 15, 2026: 284 cubic feet of water passing the gauge every second (what cfs means), or about 563 acre-feet a day. That is 20% above the 5-year median of 236 cfs for the date. A month earlier it ran 207 cfs on Sep 15, 2026, so the river has risen 37% since then. From Jackson Lake the Snake crosses southern Idaho and joins the Columbia in Washington, upstream of the Columbia River at The Dalles gauge, which counts it with the rest of the basin.
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.