The phrase "in good and bad weather" implies that something will hold up or remain consistent regardless of the conditions. Some synonyms for this phrase are "in all conditions," "in rain or shine," "come rain or come shine," "whatever the weather," and "through thick and thin." These phrases convey the idea of steadfastness and resilience despite the circumstances. Using synonyms can add variety to writing and make it more interesting to the reader. It also helps to avoid repetition and keep the text flowing. Regardless of which synonym you choose, the message is clear: the subject is reliable and unchanging, even in challenging conditions.