Aira is a Finnish name — possibly related to Iris or Eira (Welsh snow). In Finnish folklore, Aira is a name with associations to dawn and dew.
Aira is widely used in Finland.
Aira does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Aira reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.