How To See August’s Rare Blue Moon Over Washington

SEATTLE – sky watchers, take note: This weekend brings more than a short break from the stress of the work week. It also offers the chance to see a rare seasonal blue moon over Washington.

The blue moon will decorate the night sky on Sunday. The last seasonal blue moon occurred on Halloween in 2020.

There are two cases in which we experience a “blue” moon. Many of us are familiar with the first case: a blue moon occurs when there are two full moons in a calendar month. The second is usually referred to as the blue moon, according to The Farmers’ Almanac.

It turns out the story of the sentence is more muddled than you might think.

The modern custom of referring to the second full moon of the month as the “blue moon” was actually based on a misinterpretation in an article by James Hugh Pruett in the March 1946 issue of Sky & Telescope magazine. With the title “Once in a Blue Moon” Pruett misunderstood what he had read in the Maine Farmers Almanac.

The second instance – the exact definition of a blue moon and the type we’ll see on Sunday – actually has to do with the number of full moons in a single season. There are usually 12 full moons each year, or three per season. When four full moons occur during a season, the third is known as the “blue moon”.

Will you see the blue moon over Washington this year?

Possibly. On Sunday night, the skies over Puget Sound are expected to be mostly cloudy – but there’s still a good chance the blue moon will peak. If it doesn’t, your next chance to catch one is, unfortunately, three years from now.

The next seasonal blue moon will shine in the sky on August 19, 2024, followed on May 20, 2027.

So is a blue moon really blue? Usually not, according to EarthSky, org.

If you see a photo of a blue moon, it is likely that it was taken with a camera with a blue lens filter. On rare occasions, usually after major forest fires or major volcanic eruptions, the moon has reportedly turned a bluish or lavender hue, according to The Farmers’ Almanac. Soot and ash particles thrown into the earth’s atmosphere can sometimes make the moon appear blue.

That being said, a full moon wouldn’t normally appear blue in a month or any time of the year.

Since the blue moon on Sunday is significantly closer to the autumn equinox than summer, the moon has similar properties to the harvest moon in September. By definition, the harvest moon is the full moon closest to the autumn equinox. The true harvest moon will come on September 20th.