The antonyms for the phrase "more fair weather" can be "bad weather," "rainy season," or "stormy climate." These phrases suggest a departure from sunny, pleasant weather and indicate an unfavorable climate that is inclement, unpredictable, or hostile. Adverse weather conditions like heavy downpours, strong winds, lightning, and thunderstorm can disrupt outdoor activities, cause damage, and even put people's lives at risk. Hence, many people prefer to check weather forecasts before making plans and carrying appropriate gear. While fair weather may be enjoyable, it is essential to be prepared for any change in weather conditions.