"Come rain or shine" is a popular idiom used to describe someone's unwavering commitment towards a particular task or goal. There are many synonyms for this phrase that convey a similar meaning including "no matter what," "come what may," "rain or hail," and "through thick and thin." These phrases all indicate that despite adverse situations or circumstances, the person will continue to persevere and show determination towards their goal. The use of these synonyms is a great way to strengthen your language and convey a clear message of resilience and dedication.