Moon phases 2021: 12 full moons and 12 new moons

2021 has 12 full moons, 12 new moons, 12 first quarters and 13 last quarters, 49 phases in all. The first full moon falls on Thursday, 28 January 2021 at 19:16 UTC and the last on 19 December 2021 at 04:35 UTC.

When is the next full moon?

Every full moon of 2021 has already passed. The last of them was Sunday, 19 December 2021 at 04:35 UTC, 1,739 days ago. The moon is only exactly full for a moment, when it sits opposite the Sun as seen from Earth. Either side of that instant it looks full to the eye for roughly a night, which is why almanacs and local calendars often disagree by a day.

How many full moons are there in 2021?

12. There is no blue moon in 2021. Every calendar month holds exactly one full moon, so the year totals 12, one for each month. No calendar month in 2021 holds two new moons, so there is no black moon by that definition. The spacing between one full moon and the next is not fixed either: across 2021 the shortest gap is 29.31 days and the longest is 29.82 days, against a mean synodic month of 29.531 days. The moon's orbit is an ellipse and the Earth is moving around the Sun at the same time, so the interval breathes by several hours either way.

All 12 full moons of 2021

Traditional names are English folk names attached to the month, not to the moon itself, so they shift when a month carries two full moons.

When is the Harvest Moon in 2021?

The Harvest Moon is the full moon nearest the September equinox, not simply the September full moon, so in some years it lands in October. In 2021 the equinox falls at Wednesday, 22 September 2021 at 19:20 UTC and the nearest full moon is Monday, 20 September 2021 at 23:54 UTC, 1.81 days before it. That is the one to call the Harvest Moon in 2021.

What are all the moon phase dates in 2021?

The table below lists every one of the 49 phases in order, with the exact UTC instant. New moon is the moment the moon passes between Earth and Sun; full moon is the opposite alignment; the quarters are the halfway points, when exactly half the lit face is turned towards us.

How are moon phase times calculated?

These instants come from the lunation series in chapter 49 of Jean Meeus, Astronomical Algorithms. The method starts from a mean lunation counted from January 2000, then applies twenty-five periodic corrections built from the moon's mean anomaly, the Sun's mean anomaly and the moon's argument of latitude, followed by fourteen smaller planetary terms. The result is in Dynamical Time, so a delta T correction of roughly seventy seconds is subtracted to give the UT times shown here. Agreement with published tables across 2021 and the surrounding years is within half a minute.

Questions

How many full moons are in 2021?

12, the first on 28 January 2021 and the last on 19 December 2021.

Is there a blue moon in 2021?

No. Every month of 2021 has exactly one full moon.

When is the Harvest Moon in 2021?

20 September 2021, the full moon nearest the September equinox.

Are these times local?

No. Every time on this page is UTC. Convert to your own clock before planning around it.

Moon phases in other years

More for 2021

Day of the year · Event countdowns · When is it? · Date calculator