『曇り空』の例文です。
a cloudy sky in autumn（秋の曇り空 ）
the condition of being dark and cloudy（曇り空で暗いこと）
a cloudy sky of the rainy season （梅雨期の曇り空）
That is almost like a cloudy sky. （それはまるで曇り空のようです。）
It was heavy and thundery. （雷が来そうな曇り空だった.）
お役に立てたらうれしいです。
Overcast means that all the sky is covered with clouds'. If you say, "It's clouded over," it means that the sky was blue, or sparsely clouded, but now it is more or less totally cloudy.
If the sky is full of grey clouds whether it will run or not, you can use the word, "cloudy" or "overcast".
"It is looking overcast today."
"It is pretty cloudy today."
空がグレーの雲で覆われていれば、それが流れていこうが行くまいが、cloudy「曇った」や overcast「どんよりした」といった単語を使うことができます。
例）
"It is looking overcast today."
「今日はどんよりしてるね」
"It is pretty cloudy today."
「今日はえらく曇ってるね」
There are clouds in the sky, it looks as though it may rain.
There is a lot of cloud coverage, it might rain.
"There are clouds in the sky, it looks as though it may rain." The last half of the sentence is just another way of saying that there is a chance that it will rain.
"There is a lot of cloud coverage, it might rain." Cloud coverage is another way of saying that there are a lot of clouds in the sky. Both examples are just different ways of saying the same thing.
"There are clouds in the sky, it looks as though it may rain."（曇っていますね。雨が降りそうです）
- 文の後半は、雨が降るかもしれないと伝える言い方です。
"There is a lot of cloud coverage, it might rain."（雲が多いから雨が降るかもしれません）
- "Cloud coverage" は「空が曇っている」の別の言い方です。
二つの例は、同じことを別の言い方で伝えているだけです。
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