Full moons on Halloween are pretty rare.

This year will be the first Halloween in 19 years to have a full moon.

The last time there was a full moon on October 31, it was 2001 — and before that it was 1955.
The next one won't occur until 2039. In fact, the 21st century will only see six full moons on October 31: 2001, 2020, 2039, 2058, 2077 and 2096.