Okay, this is a physics/engineering question. Happily, a friend called last night to see if I wanted to go for a bike ride this morning. Just what I needed, a leisurely few laps of Prospect Park. I woke up bright and early to find out that it was raining. We texted back and forth, but ultimately agreed to give it a go. Bottom line is that it was wet but pleasant, and I'm feeling lots better for it. Only glitch was a flat on the first lap. Again, good that I had a friend along, as my spare tube and CO2 cartridges are on my other bike which is in the shop. I now owe J__ a tube and a cartridge. . .
Here's the question: Why do riders get more flats in the rain?
Oh, and one other thing, if your hands are wet, don't let the CO2 cartridge touch your bare skin when you fill the tire.