天気
てんき
tenki
= weather
In Japan, where cherry blossoms bloom on a precise schedule and typhoon season dictates summer plans, 天気 (tenki) is far more than small talk — it shapes daily decisions from whether to carry an umbrella to whether a hanami party goes ahead.
天気 (tenki) means “weather” in the sense of current atmospheric conditions — sunny, rainy, cloudy, and so on. It refers specifically to the weather of a given moment or day, distinguishing it from 気候 (kikō), which means climate or long-term weather patterns. In casual speech, 天気 appears in everyday questions like 今日の天気は？(What’s the weather today?) and in set expressions like いい天気ですね (What nice weather, isn’t it?). In formal or written contexts — weather reports, business emails mentioning outdoor events — the same word is used without change, as 天気 carries no register restriction. However, weather forecasts often pair 天気 with modifiers: 天気予報 (tenkiyohō, weather forecast) and 天気図 (tenkizu, weather map) are standard compound nouns heard daily on Japanese news.
A common confusion for learners is using 天気 when they mean 気候 (kikō). 天気 describes what the sky is doing right now or today; 気候 describes a region’s or season’s overall weather character. Say 今日は天気が悪い (The weather is bad today) but 北海道の気候は寒い (Hokkaido’s climate is cold). Also note that 天気 is a noun, so Japanese speakers say 天気がいい (the weather is good) rather than directly saying 天気いい without the が in standard speech, though dropping particles is common in very casual conversation.
天気 is written with two kanji: 天 (ten), meaning “heaven” or “sky,” and 気 (ki), meaning “air,” “energy,” or “atmosphere.” Together they form the concept of “the condition of the sky” — literally the air of the heavens. 気 appears in many weather-related and emotional words in Japanese, reflecting the classical idea that the same vital energy flows through weather, health, and mood. Recognizing 天 and 気 as individual building blocks makes a large cluster of vocabulary easier to decode.
Everyday use
今朝、隣のおじさんに会ったら「今日はいい天気ですね」と声をかけてくれた。
Kesa, tonari no ojisan ni attara ‘kyō wa ii tenki desu ne’ to koe o kakete kureta.
This morning, when I ran into my neighbor, he greeted me with ‘What nice weather today, isn’t it?’
Casual / Social Media
天気アプリを見たら午後から雨みたい。ピクニック、来週に変えない？
Tenki apuri o mitara gogo kara ame mitai. Pikunikku, raishū ni kaenai?
The weather app says it looks like rain from the afternoon. Want to move the picnic to next week?
Formal / Cultural context
お花見の日程は天気予報を確認してから決めましょう。
Ohanami no nittei wa tenkiyohō o kakunin shite kara kimemashō.
Let’s check the weather forecast before we set the date for the cherry-blossom viewing.
Weather forecasts hold unusually high cultural authority in Japan. Umbrella-carrying rates shift dramatically based on the morning news, and train platforms fill with folded umbrellas on overcast days even when rain is only a 30% chance. This stems partly from Japan’s dramatic seasonal swings — a single week in June can bring relentless 梅雨 (tsuyu) downpours, then sudden heat — making accurate 天気予報 a genuinely practical daily necessity rather than background noise.
The 梅雨 (tsuyu) rainy season, which arrives in most of Japan between June and mid-July, has made awareness of 天気 especially acute. Mold, flooding, and humidity management are real seasonal concerns, and tracking the 梅雨明け (tsuyu ake, end of rainy season) announcement from the Japan Meteorological Agency is a cultural moment in itself. Saying 梅雨明けしましたね (The rainy season has ended, hasn’t it?) carries the same shared relief as announcing a holiday.
Greeting someone with いい天気ですね (What nice weather) or 蒸し暑いですね (It’s muggy, isn’t it?) serves an important social function in Japanese culture — it opens a conversation without imposing personal topics on someone who may be a near-stranger. This weather-as-social-lubricant role means 天気 vocabulary appears far earlier and more often in real Japanese interaction than its simple N5 status might suggest.