In astrology, the summer solstice occurs in Cancer. In Western tropical astrology, the solstice marks 0° Cancer, beginning the sign traditionally associated with nurturing, home and emotional life.
This astrological placement is tied to the seasonal zodiac, which divides the ecliptic into twelve equal 30-degree signs. Cancer begins at the June solstice, Leo follows it, and Gemini precedes it in that system. The sign’s name comes from the constellation Cancer, although the sign and the modern constellation no longer occupy the same portion of the sky.
That distinction causes the most common mix-up. Because Earth’s axis slowly wobbles in a process called precession, the Sun is currently in the astronomical constellation Gemini around the Northern Hemisphere solstice. Astrology’s tropical Cancer is a coordinate in a seasonal framework; it is not a claim about the Sun’s present position against the constellation boundaries.