Yep we do. Gen is schooled in the rain as well by his trainer. Often find that if we go to a comp and its chucking it down Gen still works just fine whilst the other horses not used to it are all playing up.
I tend not to if it is already raining !!! but yesterday set off and it was nice, 10 mins into hack, totally soaked, was out so carried on, Had to wait for him to dry though to put rug back on !!!!
Must admit though - not riding today as it has not atopped at all so far, plus ankle is killing me !!