What's happening
The Sun's ingress into Pisces happens when its ecliptic longitude crosses from 30° Aquarius into 0° Pisces, the last thirty degrees of the tropical zodiac before the cycle restarts at 0° Aries. Pisces is the twelfth sign, the final mutable sign, and the pivot from the old astrological year into the new one.
The Sun spends about thirty days there. In the northern hemisphere the days begin noticeably lengthening; in the south they shorten. The ingress into Aries at the end of the month is the vernal equinox — so everything that happens in Pisces season happens in the year's antechamber, the last room before the new beginning.
The tradition
Pisces is a mutable water sign, ruled by Jupiter in classical astrology and co-ruled by Neptune in modern. The tradition describes it as the sign of dissolution, empathy, imagination, mysticism, the porous self, and the dream that does not need to be explained to be true. The Jupiter rulership is why the older sources read the sign as generous rather than merely vague — the greater benefic governing the zodiac's most boundless water, faith enlarging what planning cannot reach. Neptune's co-rulership names the same territory's modern hazards: glamour, fog, and the beautiful postponement.
Where Aquarius thought in systems, Pisces feels in atmospheres. Where the earlier signs built identity, Pisces begins the quiet dismantling of it that makes room for the next cycle to begin. The tradition treats this month as the year's closing weather — more tidal than decisive, more forgiving than efficient, and often the most creative month of the year for artists, writers, and anyone whose work depends on listening well. The twelfth sign's old association with retreat — the monastery, the studio, the sea — is practical advice wearing symbolic clothes.
How to work with it
Let things end. Clear the work that is ready to be cleared. Finish the last chapter before starting the next book. Pisces season rewards rest, art, spiritual practice, long walks without a destination, and the kind of attention that is willing to not know yet.
Treat the month as the year's composting: the projects, griefs, and identities the cycle is done with break down now into the soil the Aries equinox will plant in. The discipline is gentle but real — name what ends, forgive what failed, and resist starting anything that can wait three weeks for better fire. What genuinely cannot wait will announce itself; everything else benefits from the pause.
The shadow is avoidance dressed as surrender — the drift that never circles back to solid ground. Pisces at its best is porous without being lost; its gift is the softness that can still find the shore when the tide changes.
The simple rule
Ask what you are ready to let go of before the next cycle begins. The Sun in Pisces rewards the quiet ending more than the dramatic one.