Thanks, candiejohn.
My problem isn't getting him into the rain, it's sort of like the adage, "you can lead a horse to water, but you can't make him drink." Except that in our case it's that you can take a Basenji outside, but you can't make him potty. That stinking dog will hold it until I'm sure that his kidneys will rupture. I was concerned because I will be in classes from 8am to 5 pm, and that's a long time to wait if he refuses to potty in the morning. We'll just have to see how it goes, and hope that the umbrella and trees will provide enough cover for him to want to go.