When is the next blue moon (through 2029)?
Wondering when the next blue moon will occur? Here’s a list of the upcoming blue moons through 2029 along with a look back to the blue moons since 2010.
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.
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.
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 08:27 EST and the March blue moon was on Saturday March 31, 2018 08:37 EST.
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.
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.
When is the next blue moon?
The next calendar blue moon is Friday, August 30, 2023 21:35 EST or August 31, 2023 02:35 UTC.
The next seasonal full moon seasonal blue moon on Sunday, August 22, 2021 08:02 EST or 13:02 UTC when there will be 4 full moons during the Summer 2021 season. This full moon is also called the Full Sturgeon Moon.
In addition to the Blue Moon in 2023, there are 3 calendar blue moons coming up between now and 2027 along with 3 seasonal blue moons.
The dates and times are provided by NASA in Eastern Standard Time (EST) with Daylight Saving Time (DST) for part of the year. Also below is the Universal Time Coordinated (UTC) time. This was previously referred to at Greenwich Mean Time (GMT).
| Year | Month | Blue Moon Dates | UTC Time |
|---|---|---|---|
| 2021 | August | Sunday, August 22, 2021 08:02 EST (seasonal) | 13:02 UTC |
| 2023 | August | Friday, August 30, 2023 21:35 EST | 02:35 UTC (August 31, 2023) |
| 2025 | December | December 4, 2025 18:14 EST (seasonal) | 23:14 UTC |
| 2026 | May | Sunday, May 31, 2026 04:45 EST | 09:45 UTC |
| 2027 | May | Thursday May 20, 2027 06:59 EST (seasonal) | 11:59 UTC |
| 2029 | August | Thursday, August 23, 2029 21:51 EST (seasonal) | 02:51 UTC (August 24, 2029) |
And when was the last blue moon?
The last blue moon occurred on October 31, 2020 9:49 Eastern Time. It was the only blue moon in 2020.
Looking back from 2020 to 2010, there were 8 blue moons, and two of them were in 2018. 2018 was also an interesting year because February did not have a full moon (sometimes called a black moon).
Blue moons did not occur in 2010, 2011, 2015, or 2017.
| Year | Month | Day of the week | Past Blue Moons |
|---|---|---|---|
| 2020 | October | Saturday | October 31, 2020 09:49 EST |
| 2019 | May | Saturday | May 18, 2019 17:11 EST (seasonal) |
| 2018 | January | Wednesday | January 31, 2018 08:27 EST |
| 2018 | March | Saturday | March 31, 2018 08:37 EST |
| 2015 | July | Friday | July 31, 2015 06:43 EST |
| 2012 | August | Friday | August 31, 2012 09:58 EST |
Frequently Asked Questions
Do you have additional questions about blue moons? Here are a few questions and answers to help you.
When was the last Halloween Blue Moon?
The Last Halloween Full Blue Moon was in 2020 on Saturday October 31, 2020 09:49 EST. It was the second full moon of the Autumn 2020 season with the October 1st full moon.
When is the next Seasonal Blue Moon?
The next Seasonal Blue Moon will be on Sunday, August 22, 2021 08:02 EST or 13:02 UTC. The 2021 Summer season will have 4 full moons with the third full moon of the season being considered a Seasonal Blue Moon. The August 2021 full moon is also called the Full Sturgeon Moon.
The four full moons of the Summer 2021 season are:
- June 24, 2021 14:40 EST (18:40 UTC)
- July 23, 2021 22:37 EST (July 24, 2021 02:37 UTC)
- August 22, 2021 08:02 EST (12:02 UTC)
- September 20, 2021 19:55 EST (23:55 UTC)
The season begins with the Summer Solstice on June 20, 2021 23:32 EST or June 21, 2021 3:32 UTC. And the season ends with the Autumn Equinox on September 22, 2021 15:21 EST or 19:21 UTC.
How many blue moons were there in 2020?
In 2020 there was one blue moon that occurred on Saturday October 31, 2020 09:49 EST. It was a Halloween Full Blue Moon. It was the second full moon of the Autumn 2020 season with the October 1st full moon.
