the question that plagues the motorcycling fraternity since before 1903. Well one solution is to load up your clubs van and go to a rally anyways. I went to the Far Kew rally which is located 15 km north of Kew on the mid north coast of NSW down here. What an action packed night I had. First off i was sleeping in the van...so i didn't have to put up any tents.
Well o'k I didn't put up any tents but when i got back I had to dig a trench...I didn't like that idea as I had been drinking and the ground was clay...and it was dark..and all i had was a torch...but I got er done..all 15 feet of it..and worked great... So back to the bar...It could be that it wasn't as dark as i thought..it was till raining...ok so it gloomy..
It did't matter there were about 150 of us and even some that road bikes like about 40 of em..Thats like total dedication..
We partied all night....and the next day...I didn't drink much the next day I was saving myself...by 3pm a vote was taken, I had, downed only 2 beers the whole day..and so had another...chap. The vote was cast we packed and left..and got home at midnight...8.5 hours in solid rain...back home..Hotdam did we have fun or what...including the kindly semi driver that threw something up that smashed my front windscreen.  

If it rains well at a rally we first send the drunkest guy out to keep the fire going in the rain.  If there is cover available we try to all fit under it. If there is a bar in walking distance we'll go there.  If no cover available and no bar in walking distance, we stand in the rain and get wet!

As far as getting to and from the rally... unless it is right here in So California (where it never rains) we always have to go thru the southwest desert states where you can usually count on an afternoon rain in the summer so we either put on rain gear (if its real bad and we have a long way left to go) or we just get wet and put on dry clothes when we get there!

Oh by the way. Remember to put a crushed can under your kickstand if you are going to leave the bike at a rally in the rain. Before I figured this out I was at the Tim McGraw concert in Sturgis in pouring rain and when I came back to camp my kickstand sunk in the mud and the bike fell over.

What do I do when it rains, I normally just get wet. If I have a long day riding I will put on rain gear, but for the most part I just get wet. Here in AZ when it rains itr is normally still over 80 degrees so being cold is not a factor. And you dry off right after it stops.