Next Full Moon: Harvest Moon

Why it is called the Harvest Moon

The full moon closest to the September equinox, which can fall in September or early October.

Its name comes from the extra evening light it gave farmers finishing the harvest. Around the equinox the angle of the ecliptic to the horizon is shallow, so the moon rises soon after sunset for several nights in a row. It is the only full moon name defined by the equinox rather than the month.

Watch the moonrise on the two or three evenings around the full date; the near-continuous dusk-to-moonlight transition is the effect farmers valued.

Lore

For centuries farmers relied on the Harvest Moon's extra evening light to bring in the crops after sunset. The effect is real: near the equinox the Moon's path meets the horizon at a shallow angle, so it rises soon after sunset for several nights in a row. Harvest festivals across the northern hemisphere, from Canadian Thanksgiving to the Mid-Autumn Festival, sit close to this moon.

Trivia

• The Harvest Moon can fall in September or early October; it is the only full moon defined by the equinox rather than the month.
• 'Shine On, Harvest Moon' was a 1908 vaudeville hit that is still recorded today.
• The Mid-Autumn Festival is held on the day of this full moon in the Chinese lunar calendar.

All Harvest Moon dates ›

Gardening by the Moon

Full moon marks the turn from the waxing half of the month, when tradition favours sowing above-ground crops, to the waning half, when root crops, perennials and pruning take over. See this month's planting calendar ›

About full moons

A full moon happens when the Moon is opposite the Sun in the sky, so its entire Earth-facing side is lit. The exact moment is the same everywhere on Earth; only the clock time differs by time zone, which is why the date can shift by a day between Asia and the Americas. Full moons repeat every 29.53 days, so most years have 12 and about one year in three has 13.

A Blue Moon is a second full moon within one calendar month. A supermoon is a full moon that occurs near perigee, the Moon's closest point to Earth, and looks up to 14% larger and 30% brighter than a full moon at apogee. The traditional names come from Native American, colonial American and European almanac traditions and describe the season rather than the Moon's appearance.