天気は刻々と変わる。

天気は刻々と変わる。

The weather varies from hour to hour.

天気(てんき)は刻々(こっこく)と変(か)わる。

Tenki wa kokkoku to kawaru.

天気 (てんき)

weather; the elements; fair weather; fine weather

は (は)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

刻々 (こっこく、こくこく)

moment by moment; hour by hour

と (と)

if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)

変わる (かわる)

to change; to be transformed; to be altered; to vary; to move to; to be different; to be uncommon; to be unusual

Readings: テン、あまつ、あめ、あま-

Meanings: heavens, sky, imperial

Readings: キ、ケ、いき

Meanings: spirit, mind, air, atmosphere, mood

Readings: コク、きざ.む、きざ.み

Meanings: engrave, cut fine, chop, hash, mince, time, carving

Readings: ヘン、か.わる、か.わり、か.える

Meanings: unusual, change, strange