Sammamish Lake, WA

As of 2026-10-12, Sammamish Lake sits at 25.95 ft, which is below average for this time of year. Over the past 30 days the level has risen 0.27 ft.

The most recent reading at Sammamish Lake is 25.95 ft (2026-10-12), sourced from the U.S. Geological Survey. Readings on this page refresh automatically as the agency publishes new data.

The highest level for Sammamish Lake in our records is 31.14 ft on 1997-01-04. The lowest is 25.47 ft on 2003-09-07. Our record covers about 30 years of readings.

Compared with every October in our records, the current level is higher than 20% of them, which we classify as 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.

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 risen 0.27 ft over the past 30 days. For the operational reason on any given week, check the U.S. Geological Survey directly.

Sammamish Lake is +0.27 ft compared with this date last year (25.95 ft today). The full-history chart above covers 30 years, with a record high of 31.14 ft and a record low of 25.47 ft.