San Antonio – Have you ever heard the phrase, “once in a blue moon?” It’s typically used to describe an event that happens every "now and then” and this year, a blue moon will occur Halloween evening.
What is a ‘blue moon'?
First things first - no, the moon won’t physically appear blue. Technically, a blue moon is the second full moon in a calendar month. Although a blue moon may not be as rare as you think, it only happens on average every two to three years. The last blue moon we experienced occurred on March 31, 2018.
How rare is a Halloween full moon?
Because Halloween falls on the last calendar day of October, things have to align just right to allow for a full moon on the spookiest day of the year. According to NASA, the last time there was a full moon on Halloween was 2001, but it was only visible in the Pacific and Central time zones. With the full blue moon visible to all across the United States Saturday night, this will be the first occurrence of this event since 1944. That’s 76 years!
When will this happen again?
According to astronomers, we won’t see another 100% full moon on Halloween until 2039. After that, the coincidence will occur in 2058, 2077, and 2096.
What will the weather be like on Halloween?
It will be a beautiful day Saturday. Temperatures will fall from the upper-70s into the 60s after sunset -- a bit cool, but very nice for trick-or-treaters. Check out the full forecast here.