Harvest Moon 2021: All You Need To Know
Harvest Moon and autumn equinox
Here in the Northern Hemisphere, we call the full moon closest to the autumn equinox the Harvest Moon. In 2021, the Northern Hemisphere autumn equinox comes on September 22. The full moon falls less than two days earlier, on September 20. Thus, for the Northern Hemisphere, this upcoming full moon – the full moon closest to our autumn equinox – is our Harvest Moon.
Depending on the year, the full Harvest Moon can occur anywhere from two weeks before the autumn equinox to two weeks after. The Harvest Moon is either the last full moon of the summer season, or the first full moon in autumn. This year, the September full moon is the fourth of the season’s four full moons. That’s the fourth moon of summer for the Northern Hemisphere, and the fourth winter full moon for the Southern Hemisphere.
For the Southern Hemisphere, the Harvest Moon always comes in March or early April. It last took place on March 28, 2021, and will next happen March 18, 2022.
Most often, a season has three full moons. This time around, however, four full moons take place in one season: between the June solstice and September equinox. Four full moons in one season is quite atypical. Therefore, some people refer to the third of these four full moons as a seasonal Blue Moon.
Actually, that definition of Blue Moon preceded the better known definition. By popular acclaim, most regard a Blue Moon as the second of two full moons in one calendar month.
What is the Harvest moon?
Harvest Moon is just a name. In some ways, it’s like any other full moon name. But these autumn full moons do have special characteristics related to the time of moonrise. Nature is s particularly cooperative in giving us dusk-till-dawn moonlight, for several evenings in a row, around the time of the Harvest Moon.
On average, the full moon rises around sunset, and rises about 50 minutes later each day. But when a full moon happens close to an autumn equinox, the moon on the following nights rises closer to the time of sunset. For mid-temperate latitudes, it rises only about 20 to 25 minutes later daily for several days before and after the full Harvest Moon. . .
When is the Harvest Moon in 2021?
The exact time of the full Harvest Moon is September 20 at 23:54 Universal Time. At U.S. time zones, that translates to 8:54 p.m. ADT, 7:54 p.m. EDT, 6:54 p.m. CDT, 5:54 p.m. MDT, 4:54 p.m. PDT, 3:54 p.m Alaskan Time and 1:54 p.m. Hawaiian Time.
So watch for the Harvest Moon in late September and early October … or any of the nights around then.
By the way, more often than not, the September full moon is the Northern Hemisphere’s Harvest Moon. But if the full moon occurs in early October – as it did in 2020 – the October full moon is that year’s Harvest Moon.
https://earthsky.org/astronomy-essentials/harvest-moon-2/?