If my truck sits for several days while it is raining and damp it will not start just turns over and over but will not start until rain stops an it warms up outside
Sounds like you might be getting moisture under the distributor cap…
Check for codes or pending codes, check for spark, check fuel pressure…
Check to make sure no loose plugs at any sensors (wiggle test)…
Check battery cable ends and grounds…
If you have a decent scanner, check live data…
I think daveMP above is correct, likely some sort of problem with the high voltage part of the ignition system. Another idea, when it is damp weather (but not raining) & truck won’t start, pop open the hood and let the engine compartment air out. Might also place an electric fan to blow air across the engine. If you have a safe way to do it, you could try blowing warmed air on the dist cap and spark plug wires.
Coincidentally I did some ignition system work on my distributor equipped truck just a few weeks ago. I discovered the problem when I felt a tingle from touching a spark plug wire. Turned out that wire was faulty. My solution, I replaced all the high voltage wires with the modern silicone insulating version, and the distributor cap and rotor, now they are all making a good connection to every spark plug