You don’t want to miss the moon this weekend.
That full moon from Saturday (September 10) also bears the title of harvest moon for those living in the northern hemisphere. The moon officially becomes full when it reaches the point in the sky opposite the sun in the sky (180º). That moment occurs at 5:59 a.m. Eastern Time (0959 GMT) on Saturday.
The Saturday full moon comes closest to the September equinox, so this year it falls in September, although that title may occasionally be given to the October full moon. The 2022 version of the Harvest Moon comes unusually early, although it can occur as early as September. 8 (like 2014) or only on 10. 7 (like 1987).
Many think that the Harvest Moon stays in the night sky longer than any other full moon we see throughout the year, but that’s not the case. What sets Saturday’s full moon apart from the rest is that at the height of the current harvest season, farmers can work late into the night under the moonlight. It increases over time Sun sets, but more importantly, at this time of year, instead of reaching its normal average 50 minutes later each day, the moon appears to rise at almost the same time each night.
Below we have listed some examples for ten North American cities. Local moonrise times for September 9, 10, and 11 are given, with the mean date being the full moon of harvest.
|location||Sept 9||Sept 10||Sept 11|
|Albuquerque, New Mexico||7:25 p.m. MDT||7:55 p.m. MDT||20:23 MDT|
|Chicago||7:16 p.m. CDT||7:41 p.m. CDT||8:05 p.m. CDT|
|Denver||7:24 p.m. MDT||7:51 p.m. MDT||8:16 p.m. MDT|
|Edmonton, Alberta||20:22 MDT||8:35 p.m. MDT||8:46 p.m. MDT|
|Houston||7:32 p.m. CDT||8:06 p.m. CDT||20:38 CDT|
|los Angeles||7:11 p.m. PDT||7:42 p.m. PDT||8:11 p.m. PDT|
|Miami||7:26 p.m. EDT||8:02 p.m. EDT||8:37 p.m. EDT|
|Montreal||7:25 p.m. EDT||7:47 p.m. EDT||8:07 p.m. EDT|
|NYC||7:19 p.m. EDT||7:45 p.m. EDT||8:09 p.m. EDT|
|Seattle||7:47 p.m. PDT||8:06 p.m. PDT||8:24 p.m. PDT|
In fact, during this three-night interval, moonrise is a little over 25 minutes later on average each night for our relatively small sample — or exactly half the normal 50 minutes. A quick study of the chart shows that the night-to-night difference is greatest for the more southerly locations (Miami, located near the 26th parallel, sees the moonrise just under 36 minutes later on average). Meanwhile, in more northerly locations, the difference is smaller (in Edmonton, Alberta, at latitude 53.6ºN, the average difference is just 12 minutes).
The reason for this seasonal circumstance is that the moon appears to move alongside the moon ecliptic and at this time of year, when it rises, the ecliptic makes its smallest angle to the horizon for the inhabitants of the northern hemisphere.
In contrast, for those living in the southern hemisphere, the ecliptic appears almost perpendicular (almost at right angles) to the eastern horizon at this time of year. This means that the difference in the time of moonrise exceeds the average of 50 minutes per night. For example, in Melbourne, Australia, the difference from night to night is 72 minutes.
Interestingly, for those living near 60 degrees north latitude, the Moon actually appears to rise around the time of the Harvest Moon at the same time each night. And for those who live even further north, a paradox: the moon seems to be rising earlier! For example, in Reykjavik, Iceland (latitude 64.2º N), the times of moonrise on the 9th 9th, 10th and 11th are 8:51 PM, 8:43 PM and 8:36 PM, respectively. From Reykjavik, the moon seems to rise almost eight minutes earlier every night.
You can check out our guides for the best binoculars and the best telescopes to discover the harvest moon. If you’re hoping to capture a good photo of the moon, check out our picks for the best ones Cameras for astrophotography and The best lenses for astrophotography.
Editor’s note: If you take a picture of the Harvest Moon and would like to share it with Space.com readers, send your photos, comments, and your name and location to firstname.lastname@example.org.
Joe Rao serves as an instructor and visiting professor at New York University Hayden Planetarium (opens in new tab). He writes on astronomy for Journal of Natural History (opens in new tab)the Peasant Almanac (opens in new tab) and other publications.