1996 Blazer starting issue

I have a 1996 Blazer was running fine then day before yesterday, out of the blue it wouldn't start. I heard a single click then nothing. Had lights, horn, interior lights etc. Couldn't jump start it either. Bought a new battery, same results. Also should mention it was raining pretty hard all day long, don't know if that is important or not. Yesterday it was hot and sunny all day, came home from work last night and decided to try to start it....this time it fired right up and it's been starting fine since. I keep waiting for it to not start again, don't know if it was the starter or something to do with the rain.....any thoughts as to what may have happened or what I can check?

Two things come to mind first is like you said check the starter next i would check the safety nuetral switch if automatic or your clutch switch if manual