Verses with the word sky in the New Testament (4 verses):

Matthew 16:2
He answered and said unto them, When it is evening, ye say, It will be fair weather: for the sky is red.

Matthew 16:3
And in the morning, It will be foul weather to day: for the sky is red and lowering. O ye hypocrites, ye can discern the face of the sky; but can ye not discern the signs of the times?

Luke 12:56
Ye hypocrites, ye can discern the face of the sky and of the earth; but how is it that ye do not discern this time?

Hebrews 11:12
Therefore sprang there even of one, and him as good as dead, so many as the stars of the sky in multitude, and as the sand which is by the sea shore innumerable.