expression
rain or shine; come rain or shine
Set phrase meaning 'no matter the weather' or 'regardless of circumstances'. Often used to express unwavering commitment.
明日の試合は降っても照っても行われます。
Tomorrow's game will be held rain or shine.
彼は降っても照っても毎朝ジョギングを続けている。
He keeps jogging every morning, come rain or shine.
From 降る (to rain) and 照る (to shine), with the ～ても form meaning 'even if'. Literally 'even if it rains or shines'.