The second Full Moon of the month – Blue Moon (not necessarily blue in color) – on August 31, 2023 in Montreal, Canada. The simplified definiton of “Blue Moon” says that it is the second Full Moon in one month and the expression “once in a blue moon” means that something happens very rare, almost never.
The first Full Moon in August was on the first day of the month: August Sturgeon Moon.
August 30-31, 2023