Do supermoons always come in threes?

Like buses, perigee full moons often arrive all at once

This month brings the first of three consecutive supermoons in 2021, but this is not unusual. Indeed, every 14 lunar months the series of full Moons cycles from largest to smallest and back again as the Moon orbits Earth. Perigee can last between two and five full Moons. For a full Moon to be classed as ‘super’ it must occur when it is around 360,000km away from Earth or less, so the full Moons occurring either side commonly also fall within the supermoon category. On rare occasions we get two or four supermoons in a row, but three is the most common.