stormy weather; rough weather
Refers to weather with strong winds, heavy rain, or high waves. Often used in forecasts, maritime contexts, and formal descriptions.
Because stormy weather is expected tomorrow, the mountain climbing was canceled.
Due to rough weather, the ferry service was suspended.
荒天 is pronounced identically to 好天 but means stormy, rough weather, the near-opposite meaning, so context is essential to tell them apart.
Compound of 荒 (rough, wild) and 天 (sky, weather). The reading こうてん is the on'yomi of both characters.