I know this is going to sound very weird (well,weird is me and not a great thing) - drizzle when I started my warm up yesterday,by the time I started my run,it started getting gradually heavier,my running felt heavy and then the chest tightening reappeared. So I sadly after only 2.1km,had to concede and get back home - and walked. It can't be remotely possible that I only do as well as I do in dry conditions?
Mark
I doubt it. Have you a cap you can wear, and an inexpensive run jacket? Set yourself up to succeed and you will 🙂
Rain is actually refreshing at times and you will come to see it as a positive thing; admittedly in warmer weather 😀
I think it's unlikely! Most people actually like running in the rain as they find it refreshing. Maybe you're not warming up enough - or maybe you just don't like rain and your subconscious is sabotaging you!
In theory, it could be that you do struggle with the humidity which coincides with wet weather.
Most of us like the rain, in moderation
My husband had chest pains and we ruled out anything serious and have put it done to too heavy breathing causing muscle strain. Perhaps you're pushing yourself too much in an effort to get out of the weather? Embrace the wet and things might improve 😄
Possibly the humidity thing. Although a cold run warms me up pretty quickly. The gremlins do appear and doing my best to get those gone for good - taking some time though 
I'm being persuaded to consider HM training depending on how 10K goes but want to spend some time consolidating first.
No rush. Go at your pace. You decide when it's right for you to up the distance for a HM. Steady increase in distance, gaining fitness as you go.
Have fun 🙂
Sadly I think the gremlins have decided to move in 
Cold weather - perfect running weather
Pacemaker and running
Not strictly running related but........
