Smoke out of A/C vents

[ProjectM96]

I started my car, turned A/C on and started driving.

About 5 minutes later, white smoke started coming out of my air vents. When I turned the A/C OFF but kept the fan on, the white smoke went away.

I turned A/C back on and white smoke came out again.

This smoke is odorless.

I tried the A/C again later in the day. The White smoke did not re-appear.

It was lightly raining when this happened. Not sure if that has anything to do with it.