rain or shine 

regardless of circumstances

You will find them in the hills rain or shine.

rain or shine by The Return of Light Joker April 12, 2010

Rain or shine 

If you say that someone does something rain or shine, you mean that they do it regularly, without being affected by the weather or other circumstances.

Emily took her daughter walking every day, rain or shine.

Rain or shine by Racha îmî January 30, 2018