Waterproof Shorts

Yes, rain short are great.

Better ventilation than any trousers, even if the actual shorts aren't made of any highly waterproof / breathable fabric.

You might want to wear or carry long socks / long gaiters for more extreme conditions or use the rain shorts in combination with basic windproof trousers.

No more rain trousers for me if it is not cold.

Personally i think rainskirts are a better idea for warm and wet conditions, and they are super easy to make. They aerate and cool better than shorts, and it's not even necessary to use WPB fabric in that case–hence some light and cheap sil nylon or the like works fine. I do like tyvek rainskirts though (which is somewhat breathable–though i have no idea about the CFM levels). I've thought of making a cuben fiber rainskirt–it's the one thing in C.F. that i might be able to afford.

If you already have a Kilt, it's super easy to make–use the Kilt as the "pattern" to cut out the fabric, attach some velcro (either gluing or sewing) to two points on the fabric and voila.

Well, it's been a little over a year since posting this. I just used the WPB shorts today for a run. It's about 35 degrees F and there's a constant light rain/drizzle and a light breeze with occasional gusts. I covered about a dozen miles with about 1500ft of elevation gain in a bit over 1.5 hours.

I was a little apprehensive about using these shorts for a run as I typically wear very breathable shorts even at much lower temperatures. I was afraid they'd be clammy. It's a long enough run for me that I don't want to be uncomfortable – especially in that area.

I was wrong. They were ideal for the conditions. My lower body felt great.

My upper body didn't fare as well. I wore a wind shirt and a very light, good wicking, long sleeve baselayer. The wind shirt started leaking water through the zipper about 30 minutes into the run. The base layer wicked that and pretty soon my chest was all wet. The jacket wetted out about an hour in and my upper body was cold. I actually put my gloves back on at this point as it was a bit uncomfortable especially as the wind picked up.

I think a WPB jacket would have been overkill in this situation. Perhaps a wool baselayer would have done the trick for my upper body. I really think the WPB shorts were the ideal piece of clothing for today's conditions. I was very encouraged. These will probably take the place of WPB pants that I sometimes carry.

I don't know if this would be of any help to you or not, but golf shops often carry short sleeved waterproof/breathable golf jackets and waterproof/breathable vests.