温暖|おんだんondan[0]heiban (flat)

1. na-adjective, nounwarm; mild; temperate
   島しまの天候てんこうはとても温暖おんだんです。↗

   The island has a mild climate.

• Synonym暖かいあたたかいNeutralThe everyday word for warm; also warm-heartedness and warm colours. 「温暖」 leans written and is mostly used of climate.
• Synonym温和おんわNeutralMild of climate, but also gentle in character, speech or conduct, as in 「温和な人柄」; a wider range of use than 「温暖」.
• Synonym暖かあたたかNeutralNa-adjective, often as 「暖かな」 before a noun; also covers warmth toward people, while 「温暖」 is mainly for mild climates.
• Related生ぬるいなまぬるいNeutralLukewarm, neither hot nor cold; figuratively half-hearted, as in 「生ぬるい対応」, with a negative shade. 「温暖」 is a pleasant, comfortable warmth.
• RelatedぬるいCasualColloquial for pleasantly warm, as in 「今日はぬくい」; everyday speech usually prefers 「暖かい」, and 「温暖」 for climate.
• Related生暖かいなまあたたかいNeutralWarm in an uncomfortable, neither-here-nor-there way, as in 「生暖かい風」, often with an eerie feel; 「温暖」 is agreeable warmth.
• Antonym寒冷かんれいWrittenWritten word for cold, low temperatures, mostly of climate, as in 「寒冷地」; the opposite of 「温暖」 in climate terms.
• Antonym酷寒こっかんWrittenWritten word for severe, bitter cold, stronger than 「寒冷」; the opposite of 「温暖」 on the climate scale.

Use 「温暖」 for a mild climate; say 「暖かい」 in everyday talk, and 「温和」 for a mild, gentle character. For lukewarm or half-hearted, use 「生ぬるい」. The main antonym is 「寒冷」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 気候きこうが穏おだやかで暖あたたかい様子ようす。