In English, "cold" covers everything from cold weather to cold water to a cold personality. Japanese doesn't allow this — cold weather and cold water must use different words. This set of temperature adjectives is essential for N5 and comes up in everyday life constantly.
寒い vs 冷たい: Cold Weather vs Cold to the Touch
This is the classic temperature adjective contrast:
| Word | Reading | Meaning | Used For |
|---|---|---|---|
| 寒い | さむい | cold (weather/temperature) | ambient temperature, how you feel |
| 冷たい | つめたい | cold/cool (to the touch) | things you touch, food, drinks |
今日は寒いですね。 → It's cold today, isn't it? (weather)
この水は冷たい。 → This water is cold. (touch)
冬は寒いから、温かいコーヒーが飲みたい。 → It's cold in winter, so I want hot coffee. (寒い = weather)
冷たいビールをください。 → A cold beer, please. (冷たい = beverage temperature)
The Core Rule
- Talking about weather/climate/seasons → 寒い
- Talking about something you touch or consume → 冷たい
- Standing outside in a coat, shivering → 寒い
- Sticking your hand in ice water → 冷たい
暑い vs 熱い: Hot Weather vs Burning Hot
The exact same logic applies to "hot" — two separate words:
| Word | Reading | Meaning | Used For |
|---|---|---|---|
| 暑い | あつい | hot (weather/temperature) | ambient temperature |
| 熱い | あつい | hot/scalding (to the touch) | things you touch, food, drinks |
今日は暑いですね。 → It's hot today, isn't it? (weather)
このスープは熱いから、気をつけて。 → This soup is hot, be careful. (touch/food)
真夏は暑くて大変です。 → Midsummer is unbearably hot. (暑い = weather)
熱いお湯に入る。 → Getting into hot water. (熱い = water temperature)
The Pronunciation Trap
暑い and 熱い are pronounced exactly the same way: あつい! You can only tell them apart from context and kanji. In spoken Japanese this never causes confusion, because the situation (standing outside vs holding a cup) makes it obvious.
The Complete Temperature Adjective Chart
Let's lay out all the cold-to-hot adjectives side by side:
| Temperature | Weather/Environment | Touch/Objects |
|---|---|---|
| Cold | 寒い (さむい) | 冷たい (つめたい) |
| Cool | 涼しい (すずしい) | — |
| Warm | 暖かい (あたたかい) | 温かい (あたたかい) |
| Hot | 暑い (あつい) | 熱い (あつい) |
| Lukewarm | — | ぬるい |
A few notes:
- 涼しい is weather-only, meaning "pleasantly cool" — it's always positive. There's no touch equivalent
- 暖かい (warm weather) and 温かい (warm to touch) use different kanji but share the same reading
- ぬるい means "not hot enough" and usually carries a hint of dissatisfaction — bathwater that isn't warm enough, beer that isn't cold enough
秋は涼しくて気持ちいい。 → Autumn is cool and pleasant. (涼しい = nice weather)
ぬるいコーヒーはおいしくない。 → Lukewarm coffee doesn't taste good. (ぬるい = disappointingly tepid)
暖かい vs 温かい: Warm Weather vs Warm-Hearted
These two words are pronounced identically (あたたかい) but their kanji separates them:
| Word | Meaning | Typical Pairings |
|---|---|---|
| 暖かい | warm (weather) | 暖かい日, 暖かい春 |
| 温かい | warm (touch/emotional) | 温かいスープ, 温かい人 |
今日は暖かいですね。 → It's warm today. (weather)
温かいお茶を飲みましょう。 → Let's have some warm tea. (beverage temperature)
温かい家庭で育った。 → I grew up in a warm family. (emotional warmth)
固い vs 硬い vs 堅い: Three Kinds of "Hard"
Stepping away from temperature, let's look at another set of tactile adjectives. All three are read かたい, but with slightly different meanings:
| Word | Reading | Meaning | Typical Context |
|---|---|---|---|
| 固い | かたい | firm, solid (not easily deformed) | 固い握手, 固い決意 |
| 硬い | かたい | hard (physically stiff/tough) | 硬いパン, 硬い肉 |
| 堅い | かたい | sturdy, reliable, rigid | 堅い守り, 堅い人 (strait-laced person) |
このパンは硬い。 → This bread is hard. (physical hardness)
固い握手を交わした。 → We exchanged a firm handshake. (solid, strong)
彼は堅い人だ。 → He's a strait-laced person. (personality — rigid/serious)
In everyday life, don't overthink the three かたい. For physical hardness, 硬い is your safest bet.
心が温かい vs 心が冷たい: Warm-Hearted vs Cold-Hearted
Temperature adjectives are frequently used to describe personality in Japanese, just as in English:
| Expression | Meaning |
|---|---|
| 心が温かい人 | a warm-hearted person |
| 心が冷たい人 | a cold person |
| 冷たい態度 | a cold attitude |
| 熱い気持ち | passionate feelings |
| クールな人 | a cool person (calm/stylish) |
彼女は心が温かい人です。 → She's a warm-hearted person.
あの人は冷たい態度を取った。 → That person took a cold attitude.
Interestingly, Japanese borrowed クール (cool) from English, and just like in English, it carries the double meaning of "stylish" and "composed/calm."
Summary
- 寒い (cold weather) vs 冷たい (cold to touch) — environment vs contact
- 暑い (hot weather) vs 熱い (hot to touch) — same pronunciation, context decides
- 涼しい = pleasantly cool (weather only); ぬるい = lukewarm (with dissatisfaction)
- 暖かい (warm weather) vs 温かい (warm touch/heart) — same pronunciation, different kanji
- 固い/硬い/堅い — three kinds of かたい; for physical hardness, use 硬い
- Temperature adjectives double as personality descriptors: 温かい人 = warm-hearted, 冷たい人 = cold
Practice Quiz
Q1. 「今日は＿＿いですね」 — It's a scorching summer day. Fill in 暑 or 熱?
Show Answer
暑い
Hot weather/environment uses 「暑い」. 「熱い」 is for when you touch something scalding.
Q2. You want to order an iced coffee. How do you say it in Japanese?
Show Answer
冷たいコーヒーをください。
For cold drinks, use 「冷たい」, not 「寒い」. You can also simply say 「アイスコーヒーをください」.
Q3. 「お風呂の水が＿＿い」 — The bathwater isn't hot enough and you're not happy about it. Which word?
Show Answer
ぬるい
「ぬるい」 means "lukewarm / not hot enough" and usually implies dissatisfaction. Bathwater that should be hot but isn't is the classic ぬるい scenario.