■ Both words mean "cold," but 寒い refers to body and air temperature while 冷たい refers to anything else, generally objects.
◇Examples using 寒い:
It's cold today, isn't it.
◇Examples using 冷たい:
That water is cold.
This rice is cold.
◇Interestingly, the wind itself is 冷たい. For example, when stepping outside on a cold, windy day, a Japanese speaker's typical reactions are:
風が冷めた〜い！ The wind is cooold!
寒い！ It's cold (i.e., the weather)! (This could also mean "I'm cold.")
Point of possible confusion
You may hear people say things like 風で寒い or 風のせいで寒い. Don't let this be a cause of associating the wind with samui. These expressions mean "because of the wind, it's cold or I'm cold."
Despite all this, many citations can be found for 風が寒い, at about a ratio of 1:10 compared to 風が冷めたい in a search on Google made on this day.
When getting into water, you can use either 寒い (I'm cold) or 冷たい (the water is cold).
This is where the difference between body temperature and things becomes a little fuzzy. In general, 冷たい is used because body parts are things. The defining point is probably whether the cold is felt to be an internal issue or not. For smaller body parts such as hands, 冷たい is more common, while for larger body parts, particularly legs and sometimes arms, either works.
People who are cold or unfeeling are sometimes referred to as 冷たい.
◆Parallel examples exist for warm and hot, though only in writing:
温かい refers to warm body or air temperature (corresponding to 寒い)
暖かい refers to warm things (corresponding to 冷たい)
暑い refers to hot body or air temperature (corresponding to 寒い)
熱い refers to hot things (corresponding to 冷たい) as well as strong emotion
There are two other あつい words:
厚い thick; sometimes 分厚い is used to avoid confusion
篤い referring to serious illness and often written in hiragana あつい, as well as referring to warm-hearted emotion and also written as 暑い
This entry was created by Benjamin Barrett.