The night sky on your birthday: December 21
December 21 is day 356 of the year. Here is what the sky holds for everyone born on it — and a way to get the real sky above the exact place and hour you were born.
The Sun's constellation on December 21
On your birthday the Sun stands in front of Sagittarius, which here matches the horoscope sign Sagittarius. Because the Sun is in Sagittarius, that constellation is hidden in daylight on your birthday: you see it best around six months later.
Overhead at midnight on December 21
- Northern hemisphere (40°N — New York, Madrid, Beijing): Auriga, Taurus, Camelopardalis and Gemini; brightest stars high up: Capella (80°), Castor (69°) and Pollux (65°).
- Southern hemisphere (40°S — Melbourne, Buenos Aires region, Wellington): Columba, Carina, Puppis and Canis Major; brightest stars high up: Canopus (77°), Adhara (73°) and Sirius (65°).
Meteor showers around December 21
No major annual meteor shower is active on this date — the sky is all stars and planets.
The Moon on your next birthday
On the evening of December 21, 2026 the Moon will be waxing gibbous (93% lit): bright moonlight will wash out the faint stars.
The exact sky of the night you were born
These are averages for a latitude. Your own sky depends on the city, the year and the hour: Firmament draws the real stars, constellations, Moon and planets above your birthplace at your birth time, as a print-ready A3 poster — $4.99, delivered instantly as a PDF.
Make the sky of the night you were born — $4.99
Set your year and city on the next page; the day and month are already filled in.