Early October Climate Outlook
A La Niña Advisory was issued by the Climate Prediction Center on October 9 indicating that La Niña conditions are currently in place. La Niña conditions are the most likely scenario now through December-January-February.
Read moreSeptember 2025 Climate Summary
September 2025 was the warmest September on record in Washington back to 1895. Temperatures were +5.2°F warmer than the 1991-2020 normal when averaged statewide. Much warmer than normal temperatures observed across the eastern slopes of the Cascades and across much of eastern Washington.
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Join us for the PNW Water Summit
WHEN: November 4, 2025 7:30 am-4 pm PT (8:30 am to 5 pm MT)
WHERE: In person at Boise State University or Limited Virtual
Please register by October 30 to ensure an accurate catering count.
The Annual PNW Water Year Impacts Survey Is Now Live!
Happy 2026 Water Year! Now that water year 2025 is complete, we want to hear from you! How was the Pacific Northwest (Washington, Oregon, and Idaho) impacted?
We encourage you to fill out the PNW Water Year 2025 Impacts Survey.
September 2025 Drought and Streamflow Update
Streamflow deteriorated during September as a result of warmer than normal temperatures and a relatively slow start to the rainy season. A map of September streamflow percentiles by watershed reveals that the vast majority of watersheds are below normal or much below normal, seen in orange and brick red shading.
Read moreSeptember 2025 Notable Weather Events
September was once again a warmer than average month statewide. This was especially true across eastern Washington where prolonged warm spells with particularly warm overnight temperatures led to anomalies of around 5-8°F above normal.
Read morePlanning for Extreme Heat in Western Washington: Ongoing workshops highlight opportunities for regional collaboration and coordination
Summers in western Washington have historically been quite mild, but extreme heat has become much more common in the past couple of decades. In July of 2009, temperatures soared to 103°F in Seattle and some locations around Puget Sound rose to 100°F for the first time in recorded history.
Read moreLate September Climate Outlook
What’s Next for the Pacific Northwest?
Slight chances of above normal precipitation and temperatures for October 2025.
The Climate Prediction Center’s monthly outlook for October 2025 looks to be warm across the interior western United States with a slight chance (33-40%) of warmer than normal temperatures extending up into Washington State.
Are Washington Summers Changing? A long-term look at Washington Precipitation Trends
If you have lived in Washington for long enough, you are probably well aware that our dry and sunny summers end predictably around October or early November when fall rains and cloud cover move in.
Read moreEarly September Climate Outlook
The Climate Prediction Center issued a La Niña Watch in August. This watch means that La Niña conditions are likely to develop over the next several months, but that La Niña conditions are not currently in place.
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