This month's full moon reaches peak illumination at 12:56 p.m. EDT (17:56 GMT) and is known as the 'Flower Moon' to some in North America and Europe owing to the abundant seasonal wildflower blooms that appear during this time of year.

According to NASA, an Old English name for the May full moon is the milk moon. In 703 AD, the English monk St. Bede the Venerable wrote that May was known as the "Three-Milkings Month," likely because cows could be milked three times a day during this fertile time of year.

The moon will officially reach its fullest phase at 12:56 p.m. Eastern time on Monday, May 12, becoming the fifth of 12 full moons that will shine in 2025. If you look up in the sky Sunday night, you can see the moon at 99% illumination, followed by the completely full moon Monday night and a 99% full moon Tuesday night.