Sun in Aries
Having the Sun in Aries means you feel most like yourself at the start of things. When nobody has decided anything yet and someone has to go first, you're the one who goes.
The Sun is in Aries from about March 21 to April 19. The exact changeover shifts by a day from year to year, so if your birthday sits on either edge, check your year with the sun sign calculator.
Starting is the pleasure
Aries is the first sign of the zodiac. The Sun enters it at the March equinox, and the whole sign is about that moment of crossing a line. In daily life it looks like this: you answer the message first, you volunteer before the question is finished, you sign up and sort out the details later. Waiting for permission feels like a small physical itch.
The usual line is that Aries is competitive. What it leaves out is that you aren't very attached to the finish. Once a thing is up and running, your attention goes looking for something that hasn't started yet. Friends notice the half-built projects. You notice that most of them only existed because you went first.
The ten-minute temper
Aries is ruled by Mars, and the Mars part is real. You get angry fast and you say so. The part other sites skip is how quickly it's over. You have the argument, you say the sharp thing, and twenty minutes later you're asking what everyone wants for dinner. As far as you're concerned, the air is clear.
That's the honest tension. The other person is still standing in the argument you've already walked out of. Your cheerfulness lands as dismissal, not repair. The Aries suns who are easiest to love have worked out that their recovery time isn't everyone's, and they go back later and close the loop out loud.
What your Moon and rising do to it
Your Sun sign is the steady part of you, the thing that's still true across decades. Your Moon and rising sign decide how it comes out on an ordinary Tuesday.
An Aries sun with a Moon in Cancer or Pisces still charges in, but feels every bump on the way and is softer afterward than it looked going in. With Capricorn or Taurus rising, the speed is held behind a calm face, so people are startled when you suddenly act. With a Libra Moon, you start the fight and then immediately want everyone to be okay.
If your Moon is in Aries too, you get the undiluted version, quick in feeling as well as action: see Moon in Aries. If Aries is also your rising sign, your first impression matches the engine underneath, and strangers read you correctly within a minute: see Aries rising. The Moon needs your birth date and ideally a time; the rising sign needs the exact time and place.
Questions
What is an Aries sun personality like?
You start things before anyone else and drop arguments before anyone else. You'd rather do the wrong thing quickly and fix it than wait around for the right thing.
What's the difference between an Aries sun and Aries rising?
The Sun is who you are when you're being yourself; the rising sign is how you come across before people know you. An Aries sun with a slower rising sign gets underestimated at first, and an Aries rising with a gentler Sun gets overestimated.
Is Aries really the first sign?
Yes. The zodiac is measured from the March equinox, which is the first degree of Aries, so every astrological year opens with Aries season.