What is a blue supermoon? What to expect from tonight’s full moon

The phrase ‘blue moon’ has two meanings: in this case, a seasonal blue moon refers to the third full moon in a season that has four full moons. If you think each season is about three months long, you would usually have three moons per season, but if you end up with four in one season, the third full moon is called blue.

A full lunar cycle lasts 29.5 days, meaning that most months have one full moon, but there is the possibility for a month to have two full moons.

he second meaning for a is blue moon is when there are two full moons within a single calendar month or four full moons within a season. This is why it’s called a blue moon, -and why the saying ‘once in a blue moon’ means that something happens rarely.

Due to many wildfires happening across the globe right now, from the US to Greece, the dust from these may give the moon a red glow, rather than the ‘blue’ hue that you might expect due to the name.

The blue supermoon is due on the 19th August 2024. The sun is due to set in the UK at 20:14 tonight, so expect to see the moon in the sky from then onwards. The key is to avoid anywhere with light pollution, like main roads or cities, and hope that the sky is clear of clouds!

There are four supermoons in 2024:

• 19th August
• 18th September
• 17th October
• 15th November