快晴（かいせい、kaiseい）
- clear weather

The Japanese word 快晴 (かいせい) describes a day with clear, bright, and sunny weather. It means that the sky is free of clouds and the sun is shining brightly. It's a weather term indicating ideal conditions for outdoor activities.

⚫︎ 今日は快晴です。 Translation: Today is a clear and sunny day. ⚫︎ 快晴の下、ピクニックに行きましょう！ Translation: Let's go on a picnic under the clear sky! ⚫︎ 快晴の空の下で写真を撮りました。 Translation: I took a photo under the clear sky.

You can use 快晴 to describe the weather when talking about the day's conditions, either past, present, or future. It's often used in weather reports, news, or casual conversations. You can use it to express that the weather is favorable or suitable for outdoor activities.

快晴 is typically written in kanji as 快晴. The reading is かいせい in hiragana. It is not generally written in katakana. There are no variations in the okurigana.

⚫︎ 晴れ (はれ): Sunny, clear weather ⚫︎ 晴天 (せいてん): Clear sky, fine weather

⚫︎ 雨 (あめ): Rain ⚫︎ 曇り (くもり): Cloudy ⚫︎ 悪天候 (あくてんこう): Bad weather

明日の天気予報は快晴です。 ・Translation: The weather forecast for tomorrow is clear and sunny. ・Explanation: This sentence uses 快晴 to describe the predicted weather.

旅行中はずっと快晴で、とてもラッキーでした。 ・Translation: It was clear and sunny throughout our trip, and we were very lucky. ・Explanation: This sentence describes the weather during a trip using 快晴 to emphasize the fortunate weather conditions.

The word 快晴 is composed of two kanji: 快 (かい), meaning "pleasant" or "comfortable," and 晴 (せい), meaning "clear" or "sunny." Therefore, 快晴 literally means "pleasant clearness" or "pleasantly clear sky."