Cheerful
Jovial, Merry, Lively, Spring Season, Warm Weather
noun, な adjective
If you have a spirit of sunshine you're a really cheerful person.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
コウイチ君は本当に陽気な男の子ですね。
Koichi is a really cheerful boy.
今日みたいに温かい陽気の日にはピクニックがしたくなりますね。
A day with warm weather like today makes me want to have a picnic.
うちの家族は貧乏だが陽気だ。
My family is poor but jovial.