General fact: 30 is the height in feet that stalks of sugar cane can reach up to.
Mathematical fact: 30 is the sum of the first four squares, which makes it a square pyramidal number.
Trivia: 30 is the number of tracks on The Beatles' eponymous album, usually known as The White Album.
Historical date: January 30th is the day in 1975 that the Monitor National Marine Sanctuary is established as the first United States National Marine Sanctuary.