When was the last blue moon?
Wondering when was the last blue moon? Here’s a list of the past blue moons while looking back at the blue moons since 2010.
The dates and times provided by NASA in the United States Eastern Time are for Eastern Standard Time (EST) and Eastern Daylight Time (EDT) for part of the year in the United States. Also below is the Coordinated Universal Time (UTC) time. Since you may be in a different time zone, the exact dates may shift for your calendar.
When was the last blue moon?
The last blue moon was on Sunday, May 31, 2026 as May had two full moons. The May 31st full moon was the sixth full moon of 2026.
The last blue moon was a seasonal blue moon on Monday August 19, 2024 because summer had four full moons. The August 19th full moon was the eighth full moon of 2024.
What is a blue moon?
A blue moon is typically considered as the second of two full moons occurring in the same calendar month. While you think the saying “once in a blue moon” is a very rare occurrence, it’s a little more frequently than you realize when you watch the calendar.
Another definition of a blue moon refers to 4 full moons occurring during a season. The third full moon in that season is called a seasonal blue moon. These types of blue moons happen even more often.
The seasonal blue moon, another blue moon definition
A seasonal blue moon is the third blue moon in an astronomical season when four full moons occur within the season (Spring, Summer, Fall, and Winter). This definition is less commonly used for the blue moon because you need to look closer at the full moon cycles from December of the prior year through December of the fulling year as each winter crosses two calendar years. Astronomical seasons begin with the solstices and equinoxes each year.
The solstices, referred to as the longest or shortest day of the year, means the amount of daylight for that day. Equinoxes are when the light and dark parts of the day are the same length (equal).
- Spring starts with the spring equinox
- Summer begins with the summer solstice
- Fall starts on the fall equinox
- Winter begins with the winter solstice
The spring equinox is usually March 19th or 20th each year and the summer solstice is around June 20th or 21st. The fall equinox occurs on September 22nd or 23rd and the water solstice is usually on December 21st or 22nd each year.
How often do blue moons occur?
Generally, a blue moon only occurs about every 2 and a half years with 2 full moons in the same month. Usually, in the year that a blue moon occurs, there is only 1, but sometimes there are two such as in 2018 when both January and March had blue moons.
Past lunar eclipses during the blue moon
- March 31, 1904: Penumbral Lunar Eclipse
- January 30, 1915: Penumbral Lunar Eclipse
- January 31, 1999: Penumbral Lunar Eclipse
- December 31, 2009: Partial Lunar Eclipse
- January 31, 2018: Total Lunar Eclipse (Blood Moon)
Past Blue Moons 2010 to 2026
Looking back from 2010 to 2026, there were 12 blue moons, and two of them were in 2018. 2018 was also an interesting year because February did not have a full moon, which is also referred to as a black moon.
Blue moons did not occur in 2010, 2011, 2015, 2017, 2022, or 2025.
| Year | Month | Past Blue Moons | UTC Time |
|---|---|---|---|
| 2026 | May | May 31, 2026 at 4:45 AM EDT | 8:45 AM UTC |
| 2024 | August | August 19, 2024 at 2:26 PM EDT (seasonal) | 6:26 PM UTC |
| 2023 | August | August 30, 2023 at 9:35 PM EDT | 1:35 AM UTC (August 31) |
| 2021 | August | August 22, 2021 at 8:02 AM EDT (seasonal) | 12:02 PM UTC |
| 2020 | October | October 31, 2020 at 10:49 AM EDT | 2:49 PM UTC |
| 2019 | May | May 18, 2019 at 5:11 PM EDT (seasonal) | 9:11 PM UTC |
| 2018 | March | March 31, 2018 at 8:37 AM EDT | 12:37 PM UTC |
| 2018 | January | January 31, 2018 at 8:27 AM EDT | 1:27 PM UTC |
| 2016 | May | May 21, 2016 at 5:15 PM EDT (seasonal) | 9:15 PM UTC |
| 2015 | July | July 31, 2015 at 6:43 AM EDT | 10:43 AM UTC |
| 2013 | August | August 20, 2013 at 9:45 PM EDT (seasonal) | 1:45 AM UTC |
| 2012 | August | August 31, 2012 at 9:58 AM EDT | 1:58 PM UTC |
| 2010 | November | November 21, 2010 at 12:27 PM EST | 5:27 PM UTC |
Related: List of Blue Moons for 1900 to 2100
Blue Moons in 2018, a year worth noting
2018 was an unusual blue moon year because two blue moons occurred at the start of the year, in January and March. The January blue moon was on Wednesday January 31, 2018 at 8:27 AM EST and the March blue moon was on Saturday March 31, 2018 at 8:37 AM EDT.
As a result, February did not have a full moon at all. The lack of a full moon in a month is sometimes referred to as a black moon.
Frequently Asked Questions
Do you have additional questions about blue moons? Here are a few questions and answers to help you.
The Last Halloween Full Blue Moon was in 2020 on Saturday October 31, 2020 at 10:49 AM EDT. It was the second full moon of the Autumn 2020 season with the October 1st full moon.
In 2020 there was one blue moon that occurred on Saturday October 31, 2020. It was a Halloween Full Blue Moon. It was the second full moon of the Autumn 2020 season with the October 1st full moon.
