Service Engine light when it rains

My Service Engine Soon light comes on when it rains. As soon as I go over a puddle. Once it was accompanied with the battery light as well. After a few hours of sitting (drying out) the light shuts off.

the car runs fine during the drive in the rain though.

Any thoughts?

Have you checked to see what code is turning on the light when it comes on using either a scanner or the key dance?