The longest lunar month of the year 2014 begins with the new moon of August 25. It ends with the new moon of September 24, 2014. Follow the links below to learn more:
That’s 3 hours and 17 minutes longer than the mean lunar month of 29 days 12 hours and 44 minutes.
What is a lunar month? It’s just the duration between successive new moons. It’s also sometimes called a lunation or synodic month. Although the lunar month has a mean period of 29.53059 days (29 days 12 hours and 44 minutes), the actual length varies throughout the year.
Shortest lunar month of 2014. The shortest lunar month this year happened in between the new moons of January 30 and March 1. (There was no new moon in February 2014.) This lunar month was only 29 days 10 hours and 21 minutes long, or 2 hours and 23 minutes shorter than the mean lunar month of 29 days 12 hours and 44 minutes.
All added up, that means the year’s longest lunar month in 2014 exceeds the year’s shortest by 5 hours and 40 minutes.
Lengths of the lunar months in 2014
|Successive new moons||Length of lunar month|
|January 1 to January 30||29 days 10 hours 24 min|
|January 30 to March 1||29 days 10 hours 21 minute|
|March 1 to March 30||29 days 10 hours 45 min|
|March 30 to April 29||29 days 11 hours 30 min|
|April 29 to May 28||29 days 12 hours 26 min|
|May 28 to June27||29 days 13 hours 28 min|
|June 27 to July 26||29 days 14 hours 33 min|
|July 26 to August 25||29 days 15 hours 31 min|
|August 25 to September 24||29 days 16 hours 01 minute|
|September 24 to October 23||29 days 15 hours 43 min|
|October 23 to November 22||29 days 14 hours 36 min|
|November 22 to December 22||29 days 13 hours 04 min|
Why the difference in the lengths of lunar months? In a nutshell, the longest lunar month of the year occurs when the successive new moons coincide closely with lunar apogee – the moon’s farthest point to Earth in its orbit.
In contrast, the year’s shortest lunar month takes place when the successive new moons fall appreciably close to lunar perigee – the moon’s closest point to Earth in its orbit.
In 2014, the year’s longest and shortest lunar months do not actually showcase great extremes. In fact, the longest and shortest lunar months in the years ahead will vary more greatly from the mean.
The longest lunar months happen when successive new moons occur near lunar apogee – and in addition, the Earth is near perihelion (Earth’s closest point to the sun in its orbit). Because Earth is always closest to the sun in early January, the very longest lunar months take place in between December and January new moons.
On the other hand, extremely short lunar months happen when successive new moons fall near lunar perigee – and in addition, the Earth is near aphelion (Earth’s farthest point from the sun in its orbit). Because Earth is always at aphelion in early July, the very shortest lunar months take place in between June and July new moons.
When are the longest and shortest lunar months of 21st century? The longest lunar month of the 21st century (2001 to 2100) occurs in between the December 2017 and January 2018 new moons. With a length of 29 days 19 hours and 47 minutes, this particular lunar month exceeds the mean by a whopping 7 hours and 3 minutes.
The century’s shortest lunar month takes place in between the new moons of June and July 2053, a period of 29 days 6 hours and 35 minutes. That’s 6 hours and 9 minutes shorter than the mean.
Incidentally, exceptionally long or short lunar months repeat in cycles of 9 years.
Each year, the shortest and longest lunar months come a few months later in the year. For instance, in 2015, the shortest lunar month happens in between the April and May new moons; and the longest one in between the October and November new moons. Click here for a complete listing for the length of each lunar month in the 21st century.
Bottom line: A lunar month is the duration between successive new moons. It’s also sometimes called a lunation or synodic month. Although the lunar month has a mean period of 29.53059 days (29 days 12 hours and 44 minutes), the actual length varies throughout the year. The longest lunar month of the year begins with the new moon of August 25, 2014 and ends with the new moon of September 24, 2014.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.