Running in rain when it's +20C or more = refreshing!
Running in rain when it's +10C = mildly uncomfortable...
Running in rain when it's +2C = naaaaasty...
It wasn't intentional, I ran to the rec center where my swimming lessons are in the dry. But when I got out, it was pouring.
The worst was that my light running jacket got soaked, then it stuck to my skin. This allowed the cold to get right through to my arms. I think if I had a layer underneath - even a light one - it wouldn't have been as bad.
On the bright side, I had thin socks, so they didn't soak up water like some crappy sports socks can. Feet were fine.
Probably good experience, just a matter of time before I line up for a race in a downpour.