August 2025 Drought and Streamflow Update
Streamflow in August was slightly improved compared to July with the return of some near normal streamflow across the Olympics, western slopes of the Cascades and portions of the Columbia Basin when averaged across the month. However, much below normal streamflow continues across the eastern Cascades. Streamflow at gauges along the Wenatchee and Yakima rivers are particularly low with flows near only 30-60% of normal.
The graph below shows 7-day average runoff statewide from the beginning of the 2025 water year through August 2025. Our mid-month rain event can be seen in the relatively modest uptick in runoff (solid black line) on the right-hand side of the graph. Green shading represents near-normal runoff, while orange and brown shading represents below and much below normal runoff. This beneficial uptick in runoff helped increase streamflow and decrease river water temperatures at a crucial time for salmon. However, the impact of this rain event on our rivers was short lived as runoff dropped back to much below normal merely a week or two after the rain event.
As of August 19th, the entire state was in at least D1, Moderate Drought, according to the U.S. Drought Monitor. The last time drought conditions were in place statewide was the drought of 2015. Explore a time series of past drought conditions in Washington State using the Drought Monitor Time Series Tool. D3, Extreme Drought (red shading), remains across the northern and central Cascades and far southeastern Washington. D2, Severe Drought, remains across almost all of eastern Washington and the rest of the Cascades. D1, Moderate Drought, remains on the Olympic Peninsula and isolated pockets elsewhere.
