Red sky at night, sailor's delight; red sky in the morning, sailor's take warning.
Matthew 16:2-3
He answered and said unto them, When it is evening, ye say, It will be fair weather: for the sky is red. [3] And in the morning, It will be foul weather to day: for the sky is red and lowring. O ye hypocrites, ye can discern the face of the sky; but can ye not discern the signs of the times?