1989 Oldsmobile Delta 88 Won't start wet or damp weather.

My 89 olds does not seem to want to start sometimes, on either wet or damp days. Have only had the car a month or so and put about 400 clics on it. First time was after I washed it. Ran ok after that but would not go the next morning. Next time a week or so later on a really foggy morning, it started later that evening. Then one more time a week or so later, after a bit of a snowfall and kind of a crappy morning. Started later that afternoon. Normally it starts with just a touch of the key and runs very well?