Meaning
A person who is friendly and supportive only when things are easy or convenient, and disappears at the first sign of trouble.
It’s a criticism of loyalty specifically, not of character in general — the fair-weather friend isn’t necessarily a bad person, just an unreliable one whose presence depends entirely on circumstances being favorable.
Origin
The metaphor draws on “fair weather” as a maritime term for calm, favorable sailing conditions — a friend who is only around in fair weather is, by implication, one who disappears the moment conditions turn rough or difficult, just as a cautious sailor might avoid setting out in a storm. The exact coining is hard to pin to one date, but the underlying weather-based logic is old and widespread enough that many languages independently developed a similar image of unreliable companionship tied to good versus bad conditions, rather than the phrase spreading from English into other languages through translation.
Examples
He disappeared the moment I needed help — turns out he was just a fair-weather friend.
Don’t trust her too much, she’s known to be a fair-weather friend.
A fair-weather friend only calls when things are going well for you.
A: “Where was Mike when you were in the hospital?” B: “Nowhere, apparently he’s a fair-weather friend.”
Frequently asked questions
What does 'Fair-weather friend' mean?
A person who is friendly and supportive only when things are easy or convenient, and disappears at the first sign of trouble.
It’s a criticism of loyalty specifically, not of character in general — the fair-weather friend isn’t necessarily a bad person, just an unreliable one whose presence depends entirely on circumstances being favorable.