If you are new to out of bounds planets and using declination in astrology I recommend first reading this article to get a concisely thorough introduction to the astronomical context and history of this weird little astro-niche. There you can also find instructions on how to see if Mercury is out of bounds in your chart. If you prefer a webinar-style introduction instead, check out this video here.
Mercury is associated with reason, wit, dexterity, distribution of information, and communication in general1. According to KT Boehrer, pioneer of the study of out of bounds planets in astrology, Mercury out of bounds in the natal chart is associated with,
“Considerable imagination, great curiosity, and a talent for the acquisition of knowledge. It is sometimes indicative of an ability to master more than one language as well as a gift for mimicry in some cases. On the negative side a speech problem can be present and the native can be very shy and sometimes nervous, self-conscious.2“
Declination by KT Boehrer
Instead of manifesting in the realm of security, emotions, and family like the out of bounds Moon, with Mercury the excessively energized and “beyond ordinary”3 experience manifests in the realm of expression and communicating one’s experience out to the world. They can be workaholics like out of bounds Moon people, but rather than coming from an emotional drive to ensure safety through success, out of bounds Mercury people really just have a lot to say, so they say it. Sometimes this can get them in trouble, but such is the life of a renegade by declination.
In my own practice, I have also seen Mercury out of bounds to correlate with people who have a distinct way of communicating such as struggling immensely with speech, but excelling with the written word; a “no holds back”4 way about expressing their ideas to the world; and an exceptional talent with expression in general, whether it’s through spoken or written language, music, art, even mediumship.
Another very common theme as seen in the examples below is a remarkably extensive career in writing, singing, or acting. Themes of multiples can be greatly exaggerated. Out of bounds Mercury people aren’t afraid to dabble in different genres, try new instruments, or explore unfamiliar creative avenues of expression.
Mercury out of bounds by sign
Because of Mercury’s proximity to the Sun, it can only go out of bounds when the Sun is near it’s maximum declination at the solstice points of 0° Cancer and Capricorn. This means Mercury is only found out of bounds in a limited part of the zodiac. Mercury can be found out of bounds in the solstice signs of Cancer and Capricorn as well as the solstice bordering signs of Gemini and Sagittarius. When the Sun is at a 0° solstice point, Mercury can only ever be a maximum of 28° away at either 28° Cancer/Capricorn or 2° Gemini/Sagittarius. In both cases that’s 2° away from the non-solstice bordering fixed signs of Taurus, Leo, Scorpio, and Aquarius5.

Unlike the Moon, Mercury cannot be found out of bounds in the fixed signs of Taurus, Leo, Scorpio, and Aquarius. It can only be found in cardinal (initiatory) and mutable (transitory) signs. There is a balance of nocturnal and diurnal signs, a balance of element, but a fittingly Mercurial lack of the stabilizing influence of the fixed signs.
Mercury out of bounds in Gemini people include: Bob Dylan with Mercury as the final dispositor, Billy Joel with Mercury trine Jupiter, Ralph Waldo Emerson with Mercury square Jupiter, Darrelyn Gunzburg with Mercury ruling the midheaven in an out of sign conjunction with exalted Jupiter, Christpher Lee with Mercury on the midheaven ruling the Sun and Moon, Cyril Fagan with Mercury conjunct Neptune and Pluto.
Mercury out of bounds in Cancer people include: Della Reese with Mercury ruling the ascendant conjunct Jupiter, Gene Wilder with Mercury ruling the ascendant and Sun, Paul Gauguin with Mercury trine Neptune, Alice Bailey with Mercury square Jupiter, Kurt Browning with Mercury sextile Venus, Gary Busey with Mercury conjunct Venus (also out of bounds), Marcel Proust with Mercury conjunt Jupiter
Mercury out of bounds in Sagittarius people include: Jean Michel Basquiat with Mercury trine Uranus, Louisa May Alcott with Mercury ruling both her ascendant and midheaven, Elvis Presley with Mercury combust ruling the midheaven and opposite Pluto, Patrick Bissell with Mercury sextile Jupiter rising, John Densmore with Mercury opposite Moon and in mutual reception with Jupiter, Margot Zemach with Mercury in the 5th conjunct Venus (also out of bounds), Amos Bronson Alcott with Mercury opposite Jupiter, Bette Midler with Mercury opposite Uranus, Fyodor Dostoevsky with Mercury rising opposite Moon (also out of bounds)
Mercury out of bounds in Capricorn people include: Dolly Parton with Mercury ruling the ascendant and midheaven (and opposite out of bounds Mars), David Bowie with Mercury square Neptune, Gustave Eiffel with Mercury in a t-square involving Moon and Pluto, Max Baer Jr. with Mercury setting conjunct his chart ruler/sect light, Ed Falis with Mercury trine Pluto, Hadley Fitzgerald with Mercury ruling both the ascendant and Mars rising (also out of bounds), Patricia Neal with Mercury opposite Pluto, Naomi Judd with Mercury trine Moon
Out of bounds – now with retrogrades!
Mercury usually goes out of bounds about twice a year, sometimes up to three times, while other years only once. While out, it can remain beyond the maximum ecliptic as measured from the celestial equator for anywhere from a day or two to up to a month6,7. At the time of writing this article in 2022, Mercury most recently went out of bounds for about a week in July and will go gallivanting out again for about a month starting in November.
One significant difference between the out of bounds Mercury that distinguishes it from the out of bounds Moon is the fact that one of these celestial bodies always moves in one direct motion, while the other famously goes both ways.
It may seem ironic considering Mercury’s proximity to the Sun that it is still able to go beyond the maximum ecliptic limit by declination, but remember that like Mercury retrograde periods, the out of bounds condition is primarily based on Earth’s perspective. Mercury isn’t actually moving backwards8 in its orbit during a retrograde, nor is it flinging itself out to space when it goes out of bounds.
The graph below shows Mercury’s declination over the course of one year along with the Sun’s. It looks a lot different from the Moon’s declination over the years from the previous article. This is because unlike the Moon, Mercury isn’t orbiting Earth, but the Sun. This adds a new dynamic to consider with it’s out of bounds cycle: retrogrades.

You will notice in the graph above that the Sun’s declination makes a neat and tidy single wave, but Mercury’s moves up and down a lot more. This is due to Mercury retrograde periods, when it appears to move backwards in the sky from Earth’s perspective. Looking at the left end of the graph at the January-February columns, we can see that the Sun’s declination (orange line) is moving up from -23° toward -12°, but Mercury’s declination (blue line) starts moving in the opposite direction from -16° down to -20°. Mercury’s declination crossing over the Sun’s while moving in the opposite direction indicates retrograde motion as highlighted in the graph below.

Compare this motion relative to the celestial equator to Mercury’s motion along the ecliptic in the longitudinal graph below. The Sun’s motion through the zodiac is in orange and Mercury’s in blue. Like in the previous graph showing declination, the Sun keeps trucking along at basically the same speed and always the same direction year after year, whereas Mercury can be seen to be apparently moving backwards through the zodiac several times a year.

“When Mercury is out-of-bounds and retrograde its effects seem to carry more weight than when only retrograde”
Beyond the Solstice by Declination – Leigh Westin
According to Leigh Westin who expanded on KT Boehrer’s work, Mercury’s out of bounds period often lines up with it’s retrograde period, but not always9. More often it will line up with Mercury’s shadow period, like at the end of 2022 when Mercury spends November 24th through December 22nd out of bounds then stations retrograde a week later on December 29th. This can be seen in the graph below showing the Sun and Mercury’s declination for 2022-2023.

Mercury retrograde and out of bounds dates for 2022-202310,11:
- Jan 14, 2022 stations retrograde
- Feb 4, 2022 stations direct
- Feb 24, 2022 post-shadow end
- Apr 26, 2022 pre-shadow begin
- May 10, 2022 stations retrograde
- Jun 3, 2022 stations direct
- Jun 18, 2022 post-shadow end
- Jul 7, 2022 OOB begin
- Jul 13, 2022 OOB end
- Aug 20, 2022 pre-shadow
- Sep 10, 2022 stations retrograde
- Oct 2, 2022 stations direct
- Oct 17, 2022 post-shadow end
- Nov 24, 2022 OOB begin
- Dec 12, 2022 pre-shadow begin
- Dec 22, 2022 OOB end
- Dec 29, 2022 stations retrograde
- Jan 18, 2023 stations direct
- Feb 7, 2023 post-shadow end
- Apr 7, 2023 pre-shadow begin
- Apr 21, 2023 stations retrograde
- Jun 24, 2023 OOB begin
- Jul 7, 2023 OOB end
- Sep 15, 2023 stations direct
- Sep 30, 2023 post-shadow begin
- Nov 16, 2023 OOB begin
- Nov 25, 2023 pre-shadow begin
- Dec 13, 2023 stations retrograde
- Dec 15, 2023 OOB end
The next time Mercury will be both retrograde and out of bounds will be December 13-15, 2023 in Capricorn. The last time Mercury was both retrograde and out of bounds was May 29-30th 2021 in Gemini. You can look this up yourself with programs such as Kepler or by comparing the dates in these two handy retrograde and out of bounds calendars from Astro-Seek.
Conclusion
Mercury out of bounds is an important signature of a chart, especially for Gemini/Virgo risings as this is your chart ruler. Another time to be especially aware of of this is when Mercury progresses out of bounds. When this happens, a period of one to about thirty years is activated where there is suddenly significantly more emphasis on the communicative faculties, siblings, thought processes, short trips, etc. This can be startling to someone who is not used to out of bounds intensity in a natal placement. Astrologer Nick Dagan Best has pointed out to me that the progressed out of bounds Mercury can be even more apparent than having it natally and from researching as well as my own personal experience with Mercury progressing out of bounds earlier in my life, I can confirm!
Do you have an out of bounds Mercury? Click here to book a consultation where we can explore this placement in depth as it relates to your personal chart. To learn more about out of bounds planets and declination in astrology, click here.
1 Mercury in Astrology: Significations and meanings The Astrology Podcast
2 Declination KT Boehrer
3 Declinatin KT Boehrer
4 Introduction to Declination and Out of Bounds Planets Maighdlin Kelly
5 Beyond the Solstice by Declination Leigh Westin
6 Beyond the Solstice by Declination Leigh Westin
7 Retrograde motion can be real or illusory EarthSky
8 Beyond the Solstice by Declination Leigh Westin
9 Beyond the Solstice by Declination Leigh Westin
10 Mercury Retrograde 2002 Astro-Seek
11 Out of Bounds Declinatin Ephemeris Astro-Seek
Maighdlin M Kelly 2022