The Ram · March 21 – April 19
March 31 Zodiac Sign
Born on March 31, you're a Aries — the first sign of the zodiac — bold, driven and always ready to go first.
Zodiac sign
Element · Modality
Fire · Cardinal
Decan (second)
Sun-ruled
Birthstone
Aquamarine
Birth flower
Daffodil
Season position
Day 11 of 30
What astrology says about a March 31 birthday
March 31 is day 11 of Aries season, so astrologers link it with the sign's core character: courageous, direct, energetic, pioneering. Traits astrologers commonly associate with Aries include honest, direct communication — no hidden agendas; high energy and infectious enthusiasm; resilient: bounces back quickly from setbacks.
A commonly cited growth area for Aries: losing interest once the initial excitement fades. For the full picture of the sign, read the Aries guide.
2nd decan of Aries: Sun
Each sign is divided into three decans, 10° slices that the Sun crosses in about ten days each. March 31 falls in the second decan of Aries (about March 31 – April 9), which the traditional Chaldean system assigns to Sun. Astrologers say that adds vitality, confidence and a need to be seen.
The Sun lends a natural presence and a strong sense of self, which astrologers read as a natural presence, a strong sense of self and pride in one's work.
The number 31 in numerology
The 31 combines the 3's expressiveness with the 1's initiative. A birthday on the 31st is linked to practical creativity and the drive to turn ideas into results.
Numerology is a separate tradition from astrology and is offered here for interest.
March birthstone and flower
The modern birthstone for March is Aquamarine and the commonly listed birth flower is the daffodil. March falls in the month of the March equinox — spring in the northern hemisphere and autumn in the southern.
Aries love and compatibility
In love, Aries is a wholehearted pursuer. They enjoy the chase, say what they feel and want a partner who can match their energy rather than dim it. Grand gestures, spontaneous plans and playful competition keep the spark alive.
Astrology is a symbolic tradition, not a science, and interpretations vary between astrologers. This page is for reflection and entertainment, not prediction or advice.
Beyond your March 31 Sun sign
Your Aries Sun is one planet. Your Moon, Rising sign and the exact Sun-ruled decan details live in your full natal chart. Get yours free on Skygram.
Get my free birth chartMarch 31 birthday FAQ
What zodiac sign is March 31?
March 31 falls in Aries, which runs from March 21 to April 19 in the tropical zodiac. The Sun changes sign at a slightly different moment each year, so the boundary can fall a day or so either side of these dates. If you were born close to the edge, your birth year, time and place decide it.
Is March 31 a cusp birthday?
Not by the usual definition, which counts the first and last couple of days of a sign. March 31 is day 11 of Aries season, so it is normally read as a clear Aries birthday.
Which decan is March 31?
March 31 is in the second decan of Aries (March 31 – April 9). In the traditional Chaldean system this decan is ruled by Sun, which astrologers say adds its own flavour to Aries. Some modern astrologers assign decan rulers by element instead, which gives different planets, and decans are strictly 10° slices of the zodiac, so the date range is approximate.
What are the birthstone and flower for March?
The modern birthstone for March is Aquamarine and the birth flower is the daffodil. These come from calendar tradition rather than astrology, and the lists vary by country and source.