Sammamish Lake Water Level
Washington · updated daily from the U.S. Geological Survey
25.79 ft
Sammamish Lake is below average for this time of year and steady (-0.06 ft in the last 7 days).
Change since yesterday: -0.01 ft
Reading as of 2026-08-14 · higher than 35% of August readings on record
Where Sammamish Lake sits historically
Today's level compared with every reading in our 5.0-year record for this lake.
Since yesterday
-0.01 ft
7-day change
-0.06 ft
30-day change
-0.25 ft
1-year change
+0.04 ft
Last 30 days
Last 12 months
Full history (5.0 years)
Sammamish Lake records and averages
| Current level | 25.79 ft |
|---|---|
| Record high | 29.29 ft (2022-01-13) |
| Record low | 25.52 ft (2021-09-16) |
| Average of all readings | 26.59 ft |
| Data span | 5.0 years (1,825 readings) |
Frequently asked questions
Is Sammamish Lake full right now?
As of 2026-08-14, Sammamish Lake sits at 25.79 ft, which is below average for this time of year.Over the past 30 days the level has fallen 0.25 ft.
What is the water level at Sammamish Lake today?
The most recent reading is 25.79 ft (2026-08-14), sourced from the U.S. Geological Survey. Readings on this page refresh automatically as the agency publishes new data.
What is the highest Sammamish Lake has ever been?
The highest level in our records is 29.29 ft on 2022-01-13. The lowest is 25.52 ft on 2021-09-16. Our record covers about 5.0 years of readings.
Is Sammamish Lake low for this time of year?
Compared with every August in our records, the current level is higher than 35% of them — below average for this time of year. Seasonal comparison matters more than the raw number, because most reservoirs draw down predictably through late summer and refill over winter and spring.
Why is Sammamish Lake changing right now?
Reservoir levels move for four main reasons: rainfall and runoff into the basin, releases through the dam for downstream water supply, power generation or flood control, evaporation during hot months, and seasonal drawdown schedules set by the operating agency. Sammamish Lake has fallen 0.25 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.
How much has Sammamish Lake changed over the past year?
The level is +0.04 ft compared with this date last year (25.79 ft today). The full-history chart above covers 5.0 years, with a record high of 29.29 ft and a record low of 25.52 ft.
Nearby lakes in Washington
Source: the U.S. Geological Survey. Readings are provisional and subject to revision by the publishing agency. All Washington lake levels.