weather · noun U /ˈweð.ər/
weather
A1 the conditions in the air above the Earth such as wind, rain or temperature, especially at a particular time over a particular area
Dictionary examples:
bad/good/cold/dry/hot/stormy/warm/wet weather
The weather in the hills can change very quickly, so take suitable clothing.
We're going to have a picnic, weather permitting.
Learner example:
I need it because the weather is cold. (Key English Test; A2; Spanish)
be/feel under the weather
C2 to feel ill
Dictionary example:
I'm feeling a bit under the weather this morning.
Learner example:
Ann was a bit under the weather, [and] she felt quite lonely in her big flat. (Certificate of Proficiency in English; C2; Italian)