October 2025 Drought and Streamflow Update
On October 6, following near-record warm and dry conditions and three years of declared drought in the Yakima Basin, the Department of Ecology issued a complete halt of surface water use in the Yakima Basin. This halt impacted some users with senior water rights and was the first year in Washington State history that this action has been needed.
Thankfully, monthly streamflow has now improved in many locations across the state compared to September. The largest improvements occurred in watersheds west of the Cascade Crest. Many of these western Washington watersheds reported below or much below normal streamflow in September, but many have since recovered to near normal. October rains also improved streamflow on the far east side of the state including in the Columbia Plateau and near Spokane.
On the eastern slopes of the central and northern Cascades, rains were less abundant in the first half of the month. Therefore, many of these watersheds remained below or much below normal streamflow on a monthly basis, as seen in orange and red shading.
That being said, as of the last week of October, many of these basins have recovered to near or just above normal streamflow in the near-term. This rapid increase in streamflow and runoff in late October is shown in this graph of 7-day average statewide runoff. This is due in part to the fact that rains during the first half of the month were lighter and soils started out dry, absorbing more of the rainfall. Once heavier and more widespread rain events fell on more saturated soils later in the month, runoff and streamflow quickly increased. A steady march of precipitation systems are needed at this time of year to maintain normal streamflows moving forward.
According to the U.S. Drought Monitor, drought conditions remain across the vast majority of the state, although conditions have begun to improve. Extreme drought (brick red shading) remains across the northeastern Cascades and southeastern Washington near Pullman and Walla Walla. Moderate and Severe Drought (light and dark orange shading) exist across the vast majority of the rest of the state. Drought has ended across small portions of the Olympic Peninsula, southern coast, and in Klickitat County in southcentral Washington. Although drought has lifted in these areas, abnormally dry conditions remain in most of these spots aside from small portions of the windward slopes of the Olympic Mountains.
The map below shows the change in the U.S. Drought Monitor status over the last four weeks across the Pacific Northwest. Fall rains have led to drought improvement across Washington and the PNW, but drought conditions still remain across much of the region.
