Well we know that the werewolves come out during a full moon but what happens when there is a "blue" moon - and on Halloween night for that matter?! October 31st will be extra spooky in the Treasure Valley this year (just like the rest of 2020). A rare blue moon is expected to illuminate the sky.

A "blue moon" is the second full moon during the the same calendar month. The first full moon, known as the “harvest  moon,” happened on October 1st.  A blue moon falling on Halloween night though is actually a pretty rare occurrence.

Before we get too ahead of ourselves, the moon isn't actually going to be blue. I know, I was expecting some dope Instagram pictures to come out of this but hey, I guess that's what filters are for. A true blue moon appearing in the sky does happen every now and then though and they aren’t necessarily full. If Earth’s atmosphere is full of dust or smoke particles and the moon shines through them, the moon may have a blue-ish tint to it. So it's actually probably a good thing the moon won't actually be blue.

The last time a full moon lit up the sky on Halloweeen was all the way back in 2001. However it could only be seen in the Central and Pacific time zones. The Farmer's Almanac reports that the last time all the U.S. time zones experienced a full moon on Halloween at once was in 1944. That's 76 years ago!

If there's a time and place for extra rare things to happen though, it's here in 2020.