1. Many politicians try to say what they think their constituents want to hear, even though they don’t always mean it. The politicians look to see which way the wind blows before they speak.
2. Fred has learned to survive in his job by bending to the will and desires of each boss he has had. He sees which way the wind blows and changes his behavior accordingly.

The expression is often used in reference to a political or diplomatic situation. It has the negative connotation of being opportunistic.