Start observing the supermoon tonight and you'll see exactly why it's called the Harvest Moon

We're just days away from the Harvest Moon supermoon rising on 7 October.

But you don't need to wait until then to see a big, bright Moon in the evening sky.

As the Moon rises tonight, 5 October, it will be virtually full, and still worth observing as it ascends above the horizon.

In fact, if you observe the Moon rising over the next few nights, you'll notice it rises each evening at virtually the same time.

That's one of the things that makes the Harvest Moon unique.

Harvest Moon and a supermoon?

This October 2025 full Moon is the Harvest Moon for the year because it's the closest full Moon to the September equinox.

It's also a supermoon because the Moon is at its closest point to Earth in its orbit.

In fact, it's the first of three supermoons we'll see in 2025.

But the Harvest Moon itself is unique because its orbital geometry relative to Earth minimises the difference between rise times for the fuller phases.

That might sound a bit complex, but really all it means is that the Moon will rise at roughly the same time each evening over the course of a few nights.

While the Moon's rise location will change each night, moving slightly to the east each evening, the time it rises above the horizon virtually stays the same.

This is a result of its proximity to the September equinox, and means the big, bright Moon is reliably present at the same time each evening.

That, historically would have been of great advantage to those who had to gather the harvest at nighttime.

To put it into perspective, the average Moon rise time difference throughout the year is 50 minutes.

We can illustrate the concept with the timings for the October 2025 Harvest Moon.

Exact timings will change slightly depending on your location.

Moonrise for the 97%-lit waxing gibbous Moon on 5 October is 18:03 BST (17:03 UT).

On 6 October when virtually full, it rises just 10 minutes later at 18:13 BST (17:13 UT).

Just after full Moon on the evening of 7 October, it rises 12 minutes later at 18:25 BST (17:25 UT).

That means the Moon is above the horizon in the early evening each night from now until the Harvest Moon.

These bright Moons, which rise at roughly similar times over several evenings, are perfect for harvest collection.

Hence the name Harvest Moon.

If you observe or photograph the Harvest Moon, share your observations and images with us by emailing contactus@skyatnightmagazine.com