Why Mercury seems to move backward
Mercury never really reverses. It circles the Sun inside the Earth's orbit in 88 days, and each time it swings around the near side of the Sun, passing between the Sun and the Earth, it overtakes us. For about three weeks around that moment its path across the sky, seen from the moving Earth, runs backward against the stars: from east to west instead of west to east. Astronomers call this apparent retrograde motion. The planet slows, stops (a station), moves backward, stops again and resumes its usual direction.
How often and for how long
Mercury turns retrograde three times in most years and four times in a few: between 2000 and 2034 the four-retrograde years are 2003, 2009, 2016, 2022 and 2029. Every one of those loops lasts between 20 and 24 days, 22 on average, and Mercury spends about a fifth of its time retrograde. The station times in the tables are worked out from the site's ephemeris, which agrees with the Swiss Ephemeris within ten minutes for every Mercury station from 2000 to 2034.
The shadow before and after
A retrograde loop covers the same stretch of the zodiac three times. Mercury first crosses it moving forward, then backward during the retrograde, then forward again. That stretch is called the shadow. It runs from the degree where Mercury will turn direct to the degree where it turns retrograde.
The October 2026 loop shows how it works. Mercury enters its shadow on October 4, when it reaches 5°02′ Scorpio. It turns retrograde on October 24 at 20°59′ Scorpio, backs up to 5°02′ Scorpio and turns direct on November 13, then leaves the shadow on November 30, when it passes 20°59′ Scorpio again. Astrologers treat the pre-retrograde shadow as a preview and the post-retrograde shadow as the time for loose ends to be tied up.
Mercury retrograde in 2026 and 2027
Mercury's three yearly loops stay in the signs of one element for a few years, then shift. All three loops of 2026 fall in water signs: Pisces in February and March, Cancer in June and July, Scorpio in October and November. In 2027 each loop starts in a water sign and backs into an air sign: Pisces into Aquarius, Cancer into Gemini, Scorpio into Libra. In 2028 all three loops are in air signs: Aquarius, Gemini and Libra.
The dates on this page are given for US Eastern time. A station can fall on a different date elsewhere: the February 2026 retrograde begins at 1:47 AM Eastern on February 26, which is 10:47 PM on February 25 on the West Coast. The tables give every moment to the minute in your own time zone.
What astrologers read into it
In astrology Mercury rules communication, thinking, travel, trade and technology, so its retrograde is read as a time when those things go sideways: messages go astray, plans need a second pass and machines misbehave. The traditional advice is not to panic but to use the "re-" words: review, revise, reconsider, reconnect, repair. Astrologers suggest leaving big launches and signatures until Mercury is direct, and using the loop to finish what is already under way. These are readings from tradition, not predictions, and there is no scientific evidence that they come true.
Mercury retrograde in your own chart
About one person in five is born with Mercury retrograde, since Mercury spends about a fifth of its time that way. Astrologers read a natal Mercury retrograde as a mind that works inward: reflective, thorough and prone to rethinking. The birth chart calculator marks every retrograde planet in your chart with ℞, and the transit chart shows where today's planets fall in it.