You don’t want to miss the moon this weekend.
The full moon on Saturday (September 10) also bears the title of Harvest Moon for those who live in the northern hemisphere. The moon officially becomes full when it reaches this point in the sky opposite (180º) to the sun in the sky. That moment will occur Saturday at 5:59 a.m. EST (0959 GMT).
The Saturday full moon is the closest to the September equinox, so this year it falls in September, although on occasion that title may be bestowed on the October full moon. The 2022 version of Harvest Moon arrives exceptionally early, though it could occur as early as September 8 (as in 2014) or as late as October 7 (as in 1987).
Related: Night sky, September 2022: what you can see tonight [maps]
Many believe that Harvest Moon stays in the night sky longer than all the other full moons we see during the year, but that is not the case. What sets Saturday’s full moon apart from others is that farmers at the height of the current harvest season can work late into the night in the light of the moon. It rises around sunset, but more importantly, at this time of year, instead of increasing its normal average 50 minutes later each day, the moon appears to rise at almost the same time each night.
Below we have provided some examples for ten North American cities. Local moonrise times for September 9, 10, and 11 are provided, with the middle date being the full harvest moon.
|Location||September 9||September 10||September 11th|
|Albuquerque, New Mexico||7:25 p.m. MDT||7:55 p.m. MDT||8:23 p.m. MDT|
|Chicago||7:46 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, AB||8:22 p.m. MDT||8:35 p.m. MDT||8:46 p.m. MDT|
|Houston||7:32 p.m. CDT||8:06 p.m. CDT||8:38 p.m. 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|
|New York City||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 for our relatively small sample, moonrise occurs, on average, just over 25 minutes later each night – exactly half of the normal 50 minutes. A quick study of the chart shows that the night-to-night difference is greatest for the southernmost locations (Miami, located at a latitude near 26ºN., sees moonrise on average one just under 36 minutes later). Meanwhile, the difference is less at locations further north (in Edmonton, Alberta, located at latitude 53.6ºN, the average difference is only 12 minutes).
The reason for this seasonal circumstance is that the moon seems to move along the ecliptic and at this time of the year as it rises the ecliptic makes its smallest angle to the horizon for those living in the northern hemisphere.
In contrast, for those living in the southern hemisphere, the ecliptic at this time of year appears to stand nearly perpendicular (almost at right angles) to the eastern horizon. Thus, the difference for the time of moonrise exceeds the average of 50 minutes per night. In Melbourne, Australia, for example, the night-to-night difference is 72 minutes.
Interestingly, for those who live near 60º north latitude, the moon does indeed seem to rise at the same time each night at the time of the Harvest Moon. And for those who live even further north, paradox: the moon seems to rise earlier! In Reykjavik, Iceland (latitude 64.2ºN), for example, the moonrise times on September 9, 10, and 11 will be 8:51 p.m., 8:43 p.m., and 8:36 p.m., respectively. So from Reykjavik, the moon will appear to rise nearly eight minutes earlier each night.
You can check out our guides for the best binoculars and telescopes for spotting the Harvest Moon. If you’re hoping to capture a good photo of the moon, check out our recommendations on the best cameras for astrophotography and the best lenses for astrophotography.
Editor’s note: If you take a photo of the Harvest Moon and would like to share it with Space.com readers, send your photo(s), comments, name and location to firstname.lastname@example.org.
Joe Rao is an instructor and guest speaker at New York’s Hayden Planetarium (opens in a new tab). He writes on astronomy for natural history journal (opens in a new tab)the Farmers Almanac (opens in a new tab) and other publications.
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An early harvest moon rises on Saturday. Here’s what to expect for the September full moon.