The Moon rises about 50 minutes later each day on average, because it moves eastward around its orbit by roughly 13 degrees a day and the Earth has to turn that much further to bring it back over the horizon. The average hides a wide swing: in Dallas this week the delay runs from 27 minutes to 71 minutes, in London from 12 minutes to 88, and in Reykjavik the Hunter’s Moon will not set at all for three days. This guide explains where the number comes from, why it changes so much, and why every month has a date with no moonrise.

Where the 50 minutes comes from

The Earth turns once relative to the stars in 23 hours 56 minutes. If the Moon sat still against the stars, it would rise four minutes earlier each day, like a star does. Instead it travels all the way round the sky in 27.3 days, moving eastward, the opposite direction to the daily turning of the sky. Each day it has shifted about 13 degrees east, and the Earth needs about 50 extra minutes of rotation to catch up. Rise to rise, the lunar day is 24 hours 50 minutes on average, which is the same reason high tide comes about 50 minutes later each day.

Two things stretch and squeeze that average. The Moon’s speed along its orbit varies with its distance, from about 11.8 to 15 degrees a day, slower near apogee and faster near perigee. More important for moonrise is the angle at which the Moon’s path meets your eastern horizon, and that depends on the season, the phase and your latitude.

Why the delay is 27 minutes one week and 71 the next

Here are the measured moonrise times for Dallas from our moon calendar around the Hunter’s Moon:

  • October 21: 4:15 PM
  • October 22: 4:43 PM (28 minutes later)
  • October 23: 5:10 PM (27)
  • October 24: 5:40 PM (30)
  • October 25: 6:13 PM (33), the full Hunter’s Moon
  • October 26: 6:52 PM (39)
  • October 27: 7:38 PM (46)
  • October 28: 8:33 PM (55)
  • October 29: 9:36 PM (63)
  • October 30: 10:46 PM (70)
  • October 31: 11:57 PM (71)

In ten days the delay nearly triples. The reason is the slope of the Moon’s path where it crosses the horizon. The Moon stays close to the ecliptic, the line the Sun follows through the zodiac. On autumn evenings in the northern hemisphere the ecliptic rises from the eastern horizon at a shallow angle. The Moon’s daily 13-degree step along that line therefore carries it mostly sideways along the horizon, toward the north, and only a little below it, so the Earth needs only a short extra spin to bring it up. This is the Harvest Moon effect, and it is at its strongest for the full moons nearest the September equinox.

A week or two later, the Moon has moved on to the part of the ecliptic that stands steeply on the horizon, in Gemini and Cancer, where the same daily step drops it well below the horizon. Now the delay stretches past an hour. By the time the waning crescent rises in the small hours of early November, Dallas is back near the 50-minute average and heading the other way.

Latitude turns the dial

The further you are from the equator, the more tilted the sky, and the bigger the swing. London, at 51 degrees north, sees the Moon rise only 12 to 13 minutes later on each of October 21, 22 and 23 (4:09, 4:21 and 4:33 PM), yet by November 1 and 2 the delay is 88 and 85 minutes. Near the equator the sky’s motion is almost vertical and the slope of the ecliptic barely matters: Manila, at 14.6 degrees north, drifts gently between 37 and 57 minutes over the same fortnight, which is why the Harvest Moon is hardly a thing in the tropics.

In the southern hemisphere the calendar is reversed, because October is spring there. Sydney gets the steep side of the ecliptic at the full moon, so moonrise slips by 60 to 74 minutes a night from October 21 to 28, and then settles into a tight 27 to 28 minutes a night for the waning crescent of November 4 to 8. Australians get their equivalent of the Harvest Moon in March and April.

Three days without a moonset in Iceland

Go far enough north and the Moon can behave like the midnight Sun. From October 29 to 31 the Moon’s declination reaches 27.5 degrees north, close to the extreme it can only reach near a major lunar standstill, and the last one peaked in 2024 and 2025. Reykjavik is at 64.1 degrees north, so anything higher than 25.9 degrees north never dips below its horizon. Our calendar for Reykjavik shows moonset at 3:36 PM on October 28, then no moonset and no moonrise at all on the 29th, 30th and 31st, with the bright waning Moon simply circling the sky. It finally sets at 4:38 PM on November 1. At the same latitude in a few years’ time, when the Moon’s range has shrunk, this will not happen.

The day with no moonrise

Because the lunar day is longer than 24 hours, moonrise walks through the clock, and once a month it steps right over midnight. In Dallas the Moon rises at 11:57 PM on October 31 and next at 12:06 AM on November 2. Nothing rises on November 1, even though that Sunday is 25 hours long thanks to the end of daylight saving time. The same thing happens to moonset once a month, usually about two weeks earlier or later.

The date depends on where you live: Sydney’s gap falls on October 30, Manila’s on November 2 and London’s on November 3. If a calendar shows a dash instead of a moonrise, that is not a missing figure, it is the Moon’s long day showing through. The moon calendar handles it correctly for every city, and the free moon widget carries the same rise and set times onto your own site.

How to use this

  • Catching the full moon rising: the night after full is usually best, since the Moon comes up after sunset into a darker sky. In Dallas this month that is October 26 at 6:52 PM, eleven minutes after sunset. Our guide to the Moon illusion explains why it looks so large at that moment.
  • Planning dark skies: after full moon the Moon rises later each night, so the evening gets a longer dark window. By October 31 Dallas has more than five hours of moon-free sky after sunset.
  • Morning observers: the waning crescent rises before dawn with the smallest daily delay in spring and the largest in autumn, for northern observers.

Every figure above comes from the rise and set times computed for each city on this site. To see the pattern for your own town, open the moon phase calendar, choose your location and compare the moonrise column from one night to the next.