Temperance is from the Latin temperantia ("moderation, self-control") — one of the four classical cardinal virtues. A Puritan virtue name brought to colonial America by the Pilgrims; Temperance Wilkinson was among the early settlers of Plymouth Colony in 1620. Frances Willard's Woman's Christian Temperance Union (WCTU) was the largest American women's organization of the 19th century.
Temperance 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 Temperance reduce to 1, The Leader. This is a traditional interpretive system, not a factual claim about the name.