I don't know about your back door or yard , but I go out with my male which I also gave him a forever home and he won't go on the pad and doesn't want to get wet.
So I got him a rain coat and I stand over him with a umbrella until he go's.
I can't think of what else to do. I started to put on pad by the back door when it rain, but he will just jump on it. My girl don't want to get wet so she knowns to just go on the pad.
Wishing u Luck !!!
bark@ulater!!!!!!!
manina,miley

,max