How to see the May 2019 blue moon this weekend

This month's full moon on May 18 is going to be a blue moon, but it's not your typical blue moon.

Most people know the blue moon as the second full moon in one month, but it can also be the third of four full moons in one season, according to AccuWeather.

When this happens, it's known as a seasonal blue moon. That type of moon won't rise again until 2021.

RELATED: Blue moon, Eta Aquariids meteor shower and other May 2019 astronomy events

Don't miss the blue moon, the Eta Aquariids meteor shower and these other astronomy events happening in May 2019.