Sammamish Lake Water Level History
Thirty-day lake-level chart, recent highs and lows, net change and daily summaries from the matched USGS station.
Sammamish Lake water-level chart
Source: U.S. Geological Survey monitoring station ↗. Recent measurements may be provisional.
What has Sammamish Lake been doing?
Across the available 30-day series, Sammamish Lake is rising overall. The measured range runs from 25.66 ft to 25.9 ft, with a net change of +0.18 ft.
Lake levels can respond to rainfall, watershed inflow, dam and hydropower operations, seasonal target elevations, evaporation and downstream release requirements. This page reports what the matched sensor measured; it does not infer why an operator changed a reservoir.
Recent daily levels
| Date | Low | Average | High |
|---|---|---|---|
| Oct 7 | 25.87 ft | 25.88 ft | 25.88 ft |
| Oct 6 | 25.87 ft | 25.88 ft | 25.89 ft |
| Oct 5 | 25.87 ft | 25.88 ft | 25.89 ft |
| Oct 4 | 25.87 ft | 25.88 ft | 25.90 ft |
| Oct 3 | 25.85 ft | 25.87 ft | 25.89 ft |
| Oct 2 | 25.86 ft | 25.87 ft | 25.89 ft |
| Oct 1 | 25.86 ft | 25.87 ft | 25.88 ft |
| Sep 30 | 25.84 ft | 25.87 ft | 25.89 ft |
| Sep 29 | 25.84 ft | 25.87 ft | 25.89 ft |
| Sep 28 | 25.86 ft | 25.87 ft | 25.89 ft |
| Sep 27 | 25.84 ft | 25.87 ft | 25.90 ft |
| Sep 26 | 25.87 ft | 25.88 ft | 25.89 ft |
| Sep 25 | 25.67 ft | 25.79 ft | 25.88 ft |
| Sep 24 | 25.72 ft | 25.73 ft | 25.76 ft |
| Sep 23 | 25.71 ft | 25.74 ft | 25.75 ft |
| Sep 22 | 25.73 ft | 25.74 ft | 25.76 ft |
| Sep 21 | 25.74 ft | 25.75 ft | 25.75 ft |
| Sep 20 | 25.73 ft | 25.75 ft | 25.76 ft |
| Sep 19 | 25.73 ft | 25.75 ft | 25.76 ft |
| Sep 18 | 25.73 ft | 25.75 ft | 25.77 ft |
| Sep 17 | 25.72 ft | 25.75 ft | 25.77 ft |
| Sep 16 | 25.72 ft | 25.75 ft | 25.77 ft |
| Sep 15 | 25.74 ft | 25.75 ft | 25.76 ft |
| Sep 14 | 25.73 ft | 25.75 ft | 25.77 ft |
| Sep 13 | 25.67 ft | 25.72 ft | 25.75 ft |
| Sep 12 | 25.66 ft | 25.68 ft | 25.70 ft |
| Sep 11 | 25.67 ft | 25.68 ft | 25.72 ft |
| Sep 10 | 25.68 ft | 25.69 ft | 25.70 ft |
| Sep 9 | 25.68 ft | 25.70 ft | 25.72 ft |
| Sep 8 | 25.68 ft | 25.70 ft | 25.72 ft |
Sammamish Lake level-history FAQ
How has Sammamish Lake water level changed over the last 30 days?
Across the available 30-day sensor series, the net change is +0.18 ft and the overall direction is rising.
What was the highest Sammamish Lake level in the last 30 days?
The highest reading in the available 30-day series is 25.9 ft.
What was the lowest Sammamish Lake level in the last 30 days?
The lowest reading in the available 30-day series is 25.66 ft.
Are historical USGS lake readings final?
Not always. Recent readings may be marked provisional and can be revised by the source agency after quality review.