暖冬

1. Origins, structure, and basic meaning

• Structure: 暖冬(だんとう) means a winter warmer than in a typical year.
• Basic usage: It is used in the examples for winter-goods sales and the winter weather in a story.

2. Common pitfalls and similar expressions

• The period compared with 暖かい日
  • 暖かい日(あたたかいひ) is an individual warm day. 暖冬 describes the tendency of the winter season, so the period considered differs from that of a single day's warmth.