| April 2025 Newsletter, Climate Matters, Climate Review, Climate Variability, Drought and Soil Conditions

The Fifth Pacific Northwest Water Year 2024 Impacts Assessment

By Karin Bumbaco

The fifth Pacific Northwest (PNW) Water Year Impacts Assessment, released in March, chronicles the water year, its impacts, and how people responded across Washington, Oregon, and Idaho during the 2024 water year (October 1, 2023-September 30, 2024). The goal for this assessment, now in its fifth year, is to be a resource for future management of drought and other climate extremes. The Washington State Climate Office leads the effort, in collaboration with the University of Washington Climate Impacts Group, Oregon Climate Service, and the Idaho Department of Water Resources. The work is funded by NOAA’s National Integrated Drought Information System. See below for a few of the main findings, and take a look for yourself – we’d love to hear your thoughts.

Averaged over the water year, PNW temperatures were tied as the 4th warmest in the 129-year record, with anomalies +1.4°F above the 1991-2020 normal. The 2024 water year was also warmer than six of the last eight water years. Water year precipitation was below normal in Washington and Idaho and near-normal in Oregon. 

Similar to the 2023 water year, water year 2024 temperature anomalies were a primary driver of drought and water supply issues in Washington. First, an exceptionally warm December 2023, ranking as the 3rd warmest on record in Washington, limited snowpack growth early in the accumulation season. Second, a series of warm atmospheric rivers in January 2024 melted existing mountain snowpack. These temperature anomalies, together with slightly below normal winter precipitation, set the stage for drought early on in the year. On April 1, 2024, the statewide snowpack was only 69% of median. 

Relatively cool weather during the month of May 2024 brought a brief reprieve and helped slow the rate of snowmelt going into the summer. A whipsaw of a summer followed with a particularly warm and dry July and a wet and cool period in the latter half of August. 

But the Assessment goes well beyond merely describing the atmospheric conditions that prevailed: our primary goal is to document the various impacts and responses associated with those conditions. 

A color coded map of PNW counties showing the number of dry and wet impacts reported in the annual survey. Southwest Oregon, the Olympic Peninsula in Washington, the east slopes of the Cascade Range in Washington, the east slopes of the southern Cascade Range in Oregon, and northern Idaho have the highest number of impacts reported, between 8 and 32. The rest of the counties have either 1 to 4 impacts reported or none. Southern Idaho counties have the majority of counties with none reported.
The number of dry or wet impacts reported by Annual Pacific Northwest Water Year Impacts Survey respondents in counties in Washington, Oregon, and Idaho. White indicates that no reports were submitted for that county (Figure 19 in the PNW Water Year 2024 Impacts Assessment).

We distribute the Annual Pacific Northwest Water Year Impacts Survey at the end of the water year to identify impacts from either abnormally dry or abnormally wet conditions, and we report on the responses in the Water Year Impacts Assessment. Distribution has grown over the five years of the assessment and the 2024 survey received 358 responses. For the first time, we mapped the number of dry or wet impacts reported (see map).

We had more responses from Washington, which is likely a result of increased outreach across the state and the greater severity of drought compared to Oregon and Idaho. The greatest number of reports were from Clallam and Kittitas Counties, but because multiple reports may describe similar impacts, this doesn’t necessarily mean these counties were the most strongly impacted. Overall, more dry impacts (319) were reported compared to wet impacts (58). Of the seven sectors we asked about (drinking water, agriculture, forestry, fisheries, hydropower, recreation, stormwater), the agricultural sector reported the highest number of impacts from dry conditions.

There were 89 responses noting abnormally dry impacts for the agriculture sector. Impacts reported were less surface water and streamflow available (64%); reduced crop yield (58%); water right curtailment/reduced water allocation (48%); increased water demand due to lower than average soil moisture (48%); increased water demand (45%); reduced crop quality (45%); increased plant stress (43%); reduced pasture/forage (38%); declining groundwater levels/increased pumping costs (29%); use of a backup or alternative water source (29%); increased weed pressure (29%); animal stress (16%); increased insect infestation (12%); crop loss (or lower quality) due to wildfire (11%); increased crop disease (4%); improved crop quality (3%); and animal death (2%); and other (10%). There were 11 responses noting abnormally wet impacts for the agriculture sector. Impacts reported were reduced crop yields (45%); increased crop disease (27%); increased weed pressure (27%); increased plant stress (18%); reduced crop quality (18%); infrastructure damage (18%); delayed planting (18%); delayed harvest (18%); conditions that prevented planting (18%); increased crop yields (9%); improved crop quality (9%); and pasture/field flooding (9%).
The number and percentage of respondents that indicated the impact due to abnormally dry or abnormally wet conditions during water year 2024 for either Washington, Oregon, or Idaho.

Impacts on other sectors, and overall lessons learned from the water year are provided in the Assessment and summarized in our press release.

Finally, now that we have five water year Assessments (2020, 2021, 2022, 2023, and 2024), we are planning an evaluation study to better understand what’s working, what are the benefits, and how we might improve the Water Year meeting, impacts survey, and Assessment. Specifically, we want to know if this work is helping to build climate resilience across the Pacific Northwest. In the meantime, we invite you to participate by helping us understand and document impacts as we develop the assessment for the 2025 water year. 

You don’t have to wait until the Annual PNW Water Year Impacts Survey is released in October 2025; we encourage you to document impacts from abnormally dry or abnormally wet conditions as they happen during the water year. This can be done through the National Drought Mitigation Center’s CMOR-Drought survey, as these on-the-ground reports are also summarized in the Assessment.

We will be holding the (virtual) water year meeting in late October or early November 2025.