1.
stormy weather; rough weather; bad weather
Severe weather conditions including storms, heavy rain, strong winds, or heavy snow. A formal term used primarily in weather reports, aviation, and maritime contexts.
Usage
荒天 is a formal, written-style word typically seen in weather advisories, transportation announcements, and news reports. In everyday speech, people say 天気が悪い or 嵐 instead.
The opposite is 好天 (fine weather), which is the same reading but written with 好 instead of 荒. Context usually makes the meaning clear.