Grassy Lake and Grassy Lake water level
Lake, Wyoming, United States
Right now
Very low for mid-October
Surface elevation
- Water stored
- 6,961 acre‑ft
History
202120222023202420252026
What this means
Grassy Lake and Grassy Lake is far below normal for mid-October, with the lake level at 7,179.78 ft.
The median for mid-October is 7,198.88 ft, based on 36 years of readings, so the lake level is 19.10 ft below typical. On the same day last year the reading was 7,191.45 ft, a difference of −11.67 ft.
It has risen 0.24 ft over the past week. In the last month it has stayed between 7,178.65 ft and 7,179.78 ft.
Lakes and reservoirs often sit lower in fall after a summer of evaporation and use, and recover with winter rain and spring snowmelt.
Compared with 36 years of daily readings for this time of year. How to read levels
Key numbers
- Median for this date
- 7,198.88 ft19.10 ft below the median for this date
- Normal for this date
- 7,187.20 ft – 7,200.39 ft8 years in 10 fall in this range (36 years of records)
- Same day last year
- 7,191.45 ft−11.67 ft
- Lowest and highest in 30 days
- 7,178.65 ft – 7,179.78 ft
- Lowest and highest in 12 months
- 7,178.38 ft – 7,209.34 ft
On the water at Grassy Lake and Grassy Lake
A receding shoreline opens up beaches but also uncovers hazards: stumps, rocks and soft mud that are usually well under water.
Wear a life jacket on the water. Most boating deaths involve people who were not wearing one.
Weather at the gauge
The forecast is not available right now.
Map
Nearby gauges
| Gauge | Level | Compared with normal | 24 hours | Distance |
|---|---|---|---|---|
| Snake River above Jackson Lake at Flagg RanchRiver gauge, Snake River | 2.40 ft | Below flood stage | −0.02 ft | 8 mi |
| Fall River above Yellowstone Canal near SquirrelRiver gauge, Fall River | 431 cfs | Very low | ±0 | 17 mi |
| Fall River near SquirrelRiver gauge, Fall River | 216 cfs | Very low | +4.0 cfs | 21 mi |
| Jackson Lake and Jackson LakeLake | 6,734.21 ft | Very low | 22 mi | |
| Snake River near MoranRiver gauge, Snake River | 266 cfs | Normal | −19.0 cfs | 22 mi |
| Firehole River at Old Faithful, YNPRiver gauge, Firehole River | 37.7 cfs | Very low | −1.0 cfs | 23 mi |
| Pacific Creek at MoranRiver gauge, Pacific Creek | 4.27 ft | Below flood stage | −0.03 ft | 24 mi |
| Fall River near AshtonRiver gauge, Fall River | 445 cfs | Very low | −5.0 cfs | 27 mi |
Questions and answers
Is Grassy Lake and Grassy Lake higher than last year?
No, it is 11.67 ft lower than on the same day last year, when the reading was 7,191.45 ft.
What is a normal level for Grassy Lake and Grassy Lake in mid-October?
The median for mid-October is 7,198.88 ft. In 8 years out of 10 the reading falls between 7,187.20 ft and 7,200.39 ft, based on 36 years of records.
Is Grassy Lake and Grassy Lake really 7,179.78 ft deep?
No. 7,179.78 ft is the height of the water surface above sea level (or the agency's vertical datum), not the depth of the water.
What is the water level of Grassy Lake and Grassy Lake today?
On Oct 18, 2026, the surface elevation was 7,179.78 ft. Up 0.24 ft over the last 7 days.
Is Grassy Lake and Grassy Lake rising or falling?
Up 0.24 ft over the last 7 days.
Is the level of Grassy Lake and Grassy Lake normal?
Very low for mid-October. Compared with 36 years of daily readings for this time of year.
How often is this data updated?
The U.S. Bureau of Reclamation publishes a new reading once a day. This page refreshes within minutes of each update.
For specialists
Station codes, datum, parameters, data quality and downloads
- Operator
- U.S. Bureau of Reclamation
- Station code
usbr:7178(Agency page)- Coordinates
44.12966, -110.81939(WGS84)- Update interval
- once a day
- Licence
- Public domain. Data: U.S. Bureau of Reclamation (RISE), provisional data subject to revision
Published series
| Parameter | Last value | Time (UTC) | Quality |
|---|---|---|---|
| Surface elevation | 7,179.78 ft | 2026-10-18 06:00 | Provisional |
| Water stored | 6,961 acre‑ft | 2026-10-18 06:00 | Provisional |
Download
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How to cite
U.S. Bureau of Reclamation: Grassy Lake and Grassy Lake (usbr:7178). Accessed October 19, 2026 via Nivelmap, https://nivelmap.com/en/united-states/wyoming/grassy-lake-and-grassy-lake
How we check values
Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.
Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer