adverse / averse
Hostile conditions versus a person’s dislike.
Adverse describes things: conditions, effects, weather, rulings. Averse describes people and their reluctance, and it takes to: averse to risk. Do not use adverse to for a person’s dislike, and do not use averse weather.
Examples
Use The drug caused adverse effects.
Use They flew despite adverse weather.
Use She is averse to publicity.
Avoid She is adverse to publicity.
Avoid They flew despite averse weather.