MAsshole

I have a 91 Miata, 1.6L. I've begun to notice that whenever it's raining or misty out, the airbag light will flash. It happens mainly during start-up, but earlier in traffic I caught it flashing a few times. Anyone have any clue as to what could be causing this. The car never sustained any front-end damage, so I'm thinking maybe sensor? Thanks in advance.