Refers to the winter period as a season, often used in formal, news, or scheduling contexts.
The Winter Olympics are held once every four years.
冬季は乾燥しやすいので、加湿器を使っています。
In winter the air tends to be dry, so I use a humidifier.
The Olympics are also held during the winter season.
This restaurant closes for the winter season.
The cafe released a new drink as a winter-only item.