California stargazers should look up Sunday evening: a rare blue moon will light up the sky, and it’s the last chance to see the phenomenon for more than two years.
The second full moon of May is set to peak on Sunday, May 31, at 1:45 a.m. PT, according to the Old Farmer’s Almanac.
Here’s what else know about the upcoming blue moon, including how to snag a blue-colored beer in California.
What is a blue moon?
A monthly blue moon happens when there are two full moons in a single month, according to NASA.
The moon’s cycle, 29.5 days, is a touch shorter than the average length of a calendar month, so “eventually that gap results in a full moon happening at the beginning of a month with enough days still remaining for another full cycle ― so a second full moon in the same month,” NASA says.
“In other words, a full moon that happens on the 1st or 2nd of a month will probably be followed by a second full moon on the 30th or 31st,” NASA says.
The phenomenon happens every two to three years, according to NASA. The last monthly blue moon happened on Aug. 19, 2024.
There is also something called a “seasonal blue moon,” which happens when “there are four full moons in a single season (spring, summer, fall, and winter) instead of the usual three,” NASA said. A seasonal blue moon will happen on Aug. 19.
Sadly, with both a blue moon and a seasonal blue moon, the moon is not actually colored blue.
“The moon can appear bluish on rare occasions due to specific atmospheric conditions, but the name has nothing to do with its appearance,” The Old Farmer’s Almanac says.
The term “blue moon” dates back centuries, rooted in a mix of historical calendar discrepancies and rare atmospheric events, according to the periodical.
“The term is also used colloquially to describe anything rare — as in ‘once in a blue moon,’” The Old Farmer’s Almanac says.
When is the next blue moon?
The next monthly blue moon is on Sunday, May 31, according to The Old Farmer’s Almanac. The first full moon of the month fell on May 1.
After this upcoming blue moon, the next monthly blue moon won’t happen again until Dec. 31, 2028.
Remaining full moons of 2026
Here are the remaining full moons of 2026, according to the Old Farmer’s Almanac:
Where and when can you get a blue Blue Moon in California?
Blue Moon will be selling blue-colored beer in conjunction with the upcoming blue moon, according to the beverage’s maker Blue Moon Brewing Company.
“For one weekend only, the iconic Valencia orange is paired with the colorful twist—because while the moon in the sky can’t actually turn blue, Blue Moon can,” the company said in a news release.
Here are the bars in California slated to serve blue-colored Blue Moon between Friday, May 29, and Sunday, May 31.
Friday, May 29
Saturday, May 30
Sunday, May 31
This article originally appeared on Palm Springs Desert Sun: Blue moon peaks Sunday night in California, the last until 2028
Reporting by Daniella Segura, USA TODAY NETWORK / Palm Springs Desert Sun
USA TODAY Network via Reuters Connect
