Hanami (花見), more exactly "hana" means "flower" and "mi" comes from the verb "miru" which means "to watch", so literary means "flower viewing " . You go "hanami" anytime during the spring. You can enjoy "hanami" even into your backyard if it happens to you to have cherry trees, or plum trees, or any kind of tree that brings up flowers. I think, in Japan, if you say "hanami" the most japanese people are associating the word to going to see the cherry blossom. But this is not a fact, as they have also "Sakura matsuri" (桜祭り), "sakura" means cherry blossom, while "matsuri" means "festival". "Sakura matsuri" (the festival of cherry blossom) it is held in parks where friends, families, and ordinary people are gathering, bringing with them "bento" (home-packed meal common in Japanese cuisine), drinking sake while enjoying the cherry blossom.
The next pictures are from Sakura matsuri in Hirosaki prefecture.
The next pictures are from Sakura matsuri in Hirosaki prefecture.