Statewide conditions

As the state's lead agency for water supplies, we pay close attention to multiple data sources and monitor them closely. Rain and other precipitation, groundwater (water held in aquifers), rivers and streams, and mountain snow (snowpack) are all important contributors to water supply that we monitor.

Tacoma Old Town Dock. Photo by Wayne Hsieh, https://flic.kr/p/2pBqtCX

I want to...

What is water supply?

We rely on a variety of data sources to evaluate the state's current and future water supply.

Groundwater — water held in aquifers — is critical to the water cycle.
Surface water - precipitation, soil moisture, rivers, and streams and lowland snow are important contributors to surface water supply.
- Mountain snow acts like a water supply reservoir as it slowly melts during spring and summer.

Snowpack is an important driver of water availability in many basins. Low snowpack from a warm winter impacts timing and quantity of water in streams and rivers for farms, fish and people – including domestic drinking water. There are multiple data sources used to determine water supply.

In normal years, snowpack serves as natural storage that allowed water to gradually melt through spring and summer. This makes water available in rivers and streams for fish, farms and people when most needed. But these patterns are no longer reliable in Washington.

Snowpack supports entire ecosystems and water resources, such as drinking water and agriculture. Measuring the snowpack in the mountains helps us know how much water we'll have for the rest of the year.

In Washington, the legal definition of drought is based on water availability. A drought emergency is declared when water supply conditions are, or are expected to, fall below 75 percent of average, and there is potential for undue hardships due to low water supply. In 2020, the Legislature also authorized Ecology to issue a “drought advisory” when drought conditions are developing, but an emergency declaration is not justified.

Drought emergency declarations enable Ecology to to help mitigate the impacts of drought, lessening the negative effects it can have on water supplies for people, farms, and fish. Drought advisories are a voluntary tool to support water conservation and public readiness.

What is WSAC?

A graphic of Earth with a thermometer beside it

The Water Supply Availability Committee (WSAC) is a group of experts from state and federal agencies who evaluate statewide water supply conditions. Ecology chairs this group that provides an important consultative role to Ecology. WSAC advises Ecology on current and forecasted water supply conditions and whether the hydrologic drought threshold has been met or is likely to be met: seventy-five percent of normal water supply within a geographic area (RCW 43.83B.405 and WAC 173-166-050).

If you would like to receive notices about WSAC meetings after they are posted to this page, subscribe to the Washington Water Supply Email list.

The Water Supply Availability Committee (WSAC) meets on a monthly basis. Presentation materials and recording is now available: Water Supply Availability Committee website.

Data round-up: drought conditions summary

Below is a snapshot of wide variety of data sources that helps Ecology to understand evolving drought conditions. This will be updated regulary.

The Washington State Climate Office - Climate Outlook

Mid July Climate Outlook: Warmer and drier than normal conditions will likely persist through August
The CPCs one month outlook for August 2025 indicates elevated chances of above normal temperatures and below normal precipitation. There is a 60-70% chance of above normal temperatures across far eastern Washington. Those odds of warm conditions gradually decrease from east to west with a 40-50% chance of above normal conditions across western Washington. Precipitation, on the other hand, is only leaning slightly toward below normal conditions with a 33-40% chance of dry conditions across the western two thirds of the state and 40-50% chance of drier than normal conditions across the eastern third.
ENSO-neutral conditions are still very likely to continue through the summer and early fall according to the Climate Prediction Center (CPC). Neutral conditions typically do not play a large role in determining our average summer weather, so the outlooks discussed below are determined mostly from seasonal forecast models.
Last updated: July 17, 2025; Next update (bi-monthly): Late July

Snowpack now fully melted out from all sites (compared to normal (the 30-year average for today; info: Climate Normals | NOAA or Climatic Normals | NRCS)
83% Statewide water year to date precipitation (Down 2% from last week).
SWE Interactive Map – NWCC iMap or SWE by Basin – PDF (Why does “SWE” matter – USDA Factsheet).
Last updated: July 21, 2025; Next update (daily): July 22, 2025.

Bureau of Reclamation (BOR)

Yakima River system (Keechelus, Kachess, Cle Elum, Bumping, Rimrock) is at 47% of capacity and storage is at 59.4% of average (for this time of year).
Update: BOR announced a mid-month forecast for the July-Sept period of 42% water supply for prorated irrigation districts.
Last updated: July 21, 2025; Next update (storage-daily): July 22, 2025. Next BOR forecast will be August 7.

Northwest River Forecast Center data and information updates:

10 Day Meteorological Forests – Possible precipitation forecasted in the net two days over the Cascades, and Northeast, with minor amounts Central and Eastside. Temperatures to be above 90 throughout the ten day period on the Eastside.
Forecast report and Forecast map – Areas in North Cascades, Chelan, Okanogan/ Methow, Wenatchee, Colville, and sites in the Puget Sound, Southwest, Northwest, have May-Sept forecast below 75%, and with a combination of sites below and above 75% of normal in the far Southeast of the state.
For April-September the period, the Okanagan River is forecasted at 51% of normal, Methow at 72%, Stehekin at 71%, and Chelan at 69%.
NOTE: April – Sept forecasts are based on the next 10 days of forecast data, then based on climate Normals from 1991-2020 average.
Lasted updated: July 21, 2025; Next update(daily): July 22, 2025.

8-14 day Outlook: Below normal temperature on the Olympic Peninsula and Northwest of the state; higher than normal temperatures in Central and Eastside. Precipitation likely to be above normal (relative for summer) in Northeast, below normal in far Southwest, and near normal most of the state.
- Valid: July 28-Aug 3, 2025, Issued: July 20, 2025
July Monthly forecast: A higher probability of warmer than normal temperatures statewide and continued lean toward the likelihood of dryer than normal precipitation statewide.
Three month: Temperature and precipitation outlook (August-September-October) - Temperature likely warmer than normal statewide. Precipitation equal changes of slightly above or below normal.
- Last updated: Issued July 17, 2025; Next update (long-range) August 21, 2025

National Integrated Drought Information System (NIDIS) Drought monitor

National Drought Monitor – The three counties of Whitman, Garfield, and Asotin are now under a primary federal drought designation as portions are now in D3 status on the US Drought Monitor. Most of the Cascades and much of Central and NE are in D2 status, with other areas in D1 or abnormally dry on this tool.
Updated: July 17, 2025 (U.S. Drought Monitor map is released every Thursday morning, with data valid through Tuesday at 10am PT).

United States Geological Survey (USGS) - WA Water Science Center:

National Water Dashboard – A range of below normal, significantly low, above normal and normal flows statewide.
Last updated: July 21, 2025; Next update (daily): July 22, 2025

Other data tools used and updated:

Odds of 2024 Water Year Precipitation Reaching 100% - As of July 1, Only far NW and far SE are close to a possibility of 100% odds, while the rest of the state shows odds between 25-30% for reaching 100% of normal precipitation for water year 2025.
Climate Mapper – Mean Temperature & Precipitation Anomaly - Last 30 days - Higher than normal temperatures mostly statewide; Below normal precipitation statewide, especially in the Eastern Cascades.
PRISM Palmer Drought Severity Index – Continued drought concerns for central areas of the state, including Central and North Cascades areas.

Contact information

Caroline Mellor
Statewide Drought Lead
caroline.mellor@ecy.wa.gov
360-628-4666

Statewide conditions

I want to...

What is water supply?

Data round-up: drought conditions summary

Related links

Contact information