I think you missed Christ's points at least by half.
He made it clear that the unGodly unbelievers wouldn't have a clue.
He did also chide Believers who could tell the weather but not read the signs accurately--encouraging them to read the signs better and be alert for the end times and His return.
Believers??
Then the Pharisees and Sadducees came, and testing Him asked that He would show them a sign from heaven. He answered and said to them, "When it is evening you say, 'It will be fair weather, for the sky is red'; and in the morning, 'It will be foul weather today, for the sky is red and threatening.' Hypocrites! You know how to discern the face of the sky, but you cannot discern the signs of the times. A wicked and adulterous generation seeks after a sign, and no sign shall be given to it except the sign of the prophet Jonah." And He left them and departed. (Matt. 16)The only "sign" that Jesus was giving to the pharisees and sadducees was the sign of His resurrection. That heppened almost 2000 years ago.
I think you need ot work on the facts a bit more.