A blue supermoon appeared for a second night in a row on Thursday, giving those who missed out the first time a chance to witness the rare event.

Overcast skies and storms blocked the view for some on Australia's east coast on Wednesday evening, to the disappointment of many.

Appearing a bit bigger and brighter than normal, the moon is at both its fullest and closest point to the earth, serving up a rare treat for celestial onlookers.

A supermoon occurs when a full moon is at its closest position to earth, or roughly 363,300km away.

A blue moon is when two full moons occur in one calendar month, which takes place about 41 times each 100 years.

"If the second full moon is also a supermoon, we talk about a blue supermoon," Macquarie University astrophysics professor Richard de Grijs said.

The moon reached its fullest point about 11.30am on Thursday, but became more visible to the naked eye as the sun set.

© AAP 2023