Moon Phases September 2021
The full moon in September 2021 is on 20 September at 23:54 UTC — traditionally called the Harvest Moon. The new moon falls on 7 September at 00:51 UTC. Times are UTC.
Why the September 2021 full moon is called the Harvest Moon
The full moon falling nearest the September equinox — it rises unusually soon after sunset for several nights running, which once let farmers work late.
These are the traditional Colonial and Native American names popularised by the farmers’ almanacs. They are folklore, not astronomy — the phase dates and times on this page are computed and verifiable, the names are naming convention.
Moon phase day by day
| Day | Phase | Illumination |
|---|---|---|
| 1 | Waning Crescent | 29% |
| 2 | Waning Crescent | 21% |
| 3 | Waning Crescent | 14% |
| 4 | Waning Crescent | 7% |
| 5 | New Moon | 3% |
| 6 | New Moon | 1% |
| 7 | New Moon | 0% |
| 8 | New Moon | 3% |
| 9 | Waxing Crescent | 8% |
| 10 | Waxing Crescent | 15% |
| 11 | Waxing Crescent | 24% |
| 12 | First Quarter | 35% |
| 13 | First Quarter | 46% |
| 14 | First Quarter | 58% |
| 15 | First Quarter | 69% |
| 16 | Waxing Gibbous | 78% |
| 17 | Waxing Gibbous | 87% |
| 18 | Waxing Gibbous | 93% |
| 19 | Full Moon | 97% |
| 20 | Full Moon | 100% |
| 21 | Full Moon | 100% |
| 22 | Full Moon | 97% |
| 23 | Waning Gibbous | 94% |
| 24 | Waning Gibbous | 88% |
| 25 | Waning Gibbous | 81% |
| 26 | Waning Gibbous | 73% |
| 27 | Last Quarter | 65% |
| 28 | Last Quarter | 55% |
| 29 | Last Quarter | 46% |
| 30 | Last Quarter | 36% |
Illumination at noon (UTC) for each day.
Frequently asked questions
When is the full moon in September 2021?
The full moon in September 2021 is on 20 September at 23:54 UTC, traditionally called the Harvest Moon.
What time is the full moon in September 2021?
The moon reaches full phase at 23:54 UTC on 20 September. It looks full to the naked eye for about a day either side of that instant, so the nights before and after are both worth watching.
Why is the September 2021 full moon called the Harvest Moon?
The full moon falling nearest the September equinox — it rises unusually soon after sunset for several nights running, which once let farmers work late. These names come from Colonial and Native American tradition and were popularised by the farmers' almanacs — they are naming convention rather than astronomy, while the phase dates and times on this page are computed and verifiable.
When is the new moon in September 2021?
The new moon in September 2021 is on 7 September at 00:51 UTC.