Next Blue Moon to Grace Canadian Skies in May 2026
TORONTO, January 22, 2026 – The phrase “once in a blue moon” refers to a rare event, but the celestial phenomenon itself is more frequent than the idiom suggests. Skywatchers across Canada can mark their calendars for the next Blue Moon, which will occur on May 31, 2026.
What is a Blue Moon?
Contrary to its name, a Blue Moon is not typically blue in colour. The term has two primary definitions in modern astronomy and folklore. The first, known as a seasonal Blue Moon, is the third full moon in an astronomical season that contains four full moons. The second, and more commonly known definition, is a monthly Blue Moon, which is the second full moon to occur within a single calendar month.
The lunar cycle is approximately 29.5 days, slightly shorter than the average calendar month. This discrepancy allows for two full moons to occasionally fit within the same 30 or 31-day month, with the second one earning the “blue” designation.
Key Facts & Upcoming Dates
| Event | Date (UTC) | Notes for Canada |
|---|---|---|
| Next Monthly Blue Moon | May 31, 2026 | Will be visible as the second full moon in May 2026. Also classified as a “micromoon” for being at its farthest point from Earth. |
| Next Seasonal Blue Moon | May 20, 2027 | The third of four full moons between the March equinox and June solstice. |
| Last Blue Moon | August 19, 2024 | Was a seasonal Blue Moon and also a supermoon. |
| Frequency | ~2.5 years | Blue Moons occur, on average, once every 2 to 3 years. |
Folklore and Modern Origins
The seasonal definition is the older of the two, with references traced to a 1937 Maine Farmers’ Almanac. The now-popular monthly definition originated from a misinterpretation in a 1946 issue of Sky & Telescope magazine. This definition was later popularized in the 1980s through radio shows and the board game Trivial Pursuit, cementing its place in modern folklore.
Globally, many cultures attach superstitions to the Blue Moon, viewing it as a time for wishes, renewal, or increased spiritual activity. In a uniquely Canadian note, the popular Belgian-style wheat ale known as “Blue Moon” in the United States is sold under the name “Belgian Moon” in Canada due to prior trademark registrations.
Will the Moon Actually Be Blue?
While the May 2026 moon will not appear blue, a truly blue-coloured moon is possible under rare atmospheric conditions. This can occur when particles of a specific size, such as those from massive volcanic eruptions or large forest fires, scatter red light in the atmosphere. Historical instances include the aftermath of the 1883 Krakatoa eruption and smoke from Canadian forest fires in 1950 that reportedly caused blue moons across eastern North America and parts of Europe.
How to Observe
The Blue Moon on May 31, 2026, will be visible across Canada, weather permitting. As a “micromoon,” it will appear slightly smaller in the sky than an average full moon. No special equipment is needed to enjoy the sight. For precise moonrise times in your city, consult local astronomical resources or planetarium websites.
Frequently Asked Questions
How often does a Blue Moon happen?
Blue Moons occur, on average, every 2 to 3 years. The phrase “once in a blue moon” implies greater rarity than the astronomical event itself.
Can there be two Blue Moons in one year?
Yes, but it is uncommon. This can happen in a year where February has no full moon, leading to two full moons in both January and March. The next year with two monthly Blue Moons will be 2037.
Is the Blue Moon in May 2026 a supermoon?
No. The May 31, 2026, Blue Moon is classified as a “micromoon,” meaning it will occur when the moon is near its farthest point from Earth (apogee) and will appear slightly smaller than average.