'Sky' in the Bible

But in answer he said to them, At nightfall you say, The weather will be good, for the sky is red.

And in the morning, The weather will be bad today, for the sky is red and angry. You are able to see the face of heaven, but not the signs of the times.

For as in a thunderstorm the bright light is seen from one end of the sky to the other, so will the Son of man be when his time comes.