Originally Posted by Maelochs

I have seen this. Riders are sweating and loving a rain ride, but as soon as they stop and stop pumping out all that wattage, they start shivering because they are soaked and using whatever body temp they have heating and evaporating water, not staying warm.

I'd say the most important hing if you are riding distance in summer rain is what you wear right off the bike. breathability isn't such an issue of you are stopped, but heat loss is.

While exercising your body produces all the heat you need.

I used to live in New England and have gone running in snow in shorts and a short-sleeved sweatshirt. Absolutely no issue ... except if you stop, you die.