Suvi is from the Finnish suvi — summer (archaic/poetic form of kesä). Suvi is one of the Finnish feminine names — central to traditional Finnish seasonal naming alongside Talvi (winter), Kesä (summer), Sade (rain), and Helmi (pearl).
Suvi 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 Suvi reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.