Our monthly newsletter features a Climate Matters article, detailing a specific aspect of Washington’s weather and climate. These articles are archived here and categorized by topic area and date.
December 8-11, 2025 Heavy Rainfall and Flooding: Historical Context and a Note on Snow Drought
Event recap
Major flooding impacted western Washington and the eastern Cascades last month. Impacts included numerous washouts and landslides on roadways including a weeks-long shutdown of US-2 and lane closures on I-90.
Climate Matters: The CoCoRaHS Rain Gauge Network and a Tale of Two Hydrologic Extremes
On November 14-15, 2021, 4.67” of rain fell at Bellingham International Airport, setting a new record for that location. This storm brought with it the most devastating flood that Whatcom County has seen in decades.
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Climate Matters: Water Year 2025 in Review
Water year 2025 is complete, and it’s time to take a look back and see how WA stacked up historically. The 2025 water year includes the 12 months from October 1, 2024 through September 30, 2025, as opposed to the usual calendar year.
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Climate Matters: Haven’t there been a lot of La Niña winters lately?
Many regular readers of this column are aware of the effects of La Niña, and variations in the El Niño-Southern Oscillation (ENSO) in general, on the overall weather of the Pacific Northwest during the cool season.
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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.
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Our Afternoon Heat Comes Later
Editor’s note (08/13/2025 4:30pm): Time of day was previously shown in standard time on the graphs below, in error. The graphs and text are now updated to Pacific Daylight Time.
One of the things I really appreciate about living here is how late it stays light out.
A New Paper Synthesizing Studies on the June 2021 Pacific Northwest Heat Wave Now Available
The June issue of the Bulletin of the American Meteorological Society (BAMS) featured a new paper synthesizing over 70 articles on the record-breaking June 2021 Pacific Northwest (PNW) heat wave. I am a co-author on the article, collaborating with experts at Oregon State University and Portland State University.
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Climatology of the Northeastern Washington Climate Division (#9)
In this edition of Climate Matters, we return to our Climate Division series in which we describe the local climate features in each of Washington’s 10 climate divisions, as defined by NOAA.
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Trends in the Timing of Spring Across Washington
There are a truly dizzying number of ways to measure the start of spring: Is it when lilacs start blooming and grapevines begin to leaf out? Or is it that first warm day of the season when local parks fill up?
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The Fifth Pacific Northwest Water Year 2024 Impacts Assessment
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).
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