It's funny, if I had to pick pipe smoking to overlap with one activity, I would have said fly fishing. Probably based on the contemplative and to a degree ritualistic nature of both. That's just based on my experience in New England, not sure about everywhere else. But among fly fisherman was the only time that smelling someone's pipe smoke didn't come as a surprise, albeit a pleasant one.
For my own hobbies, it used to be reading, hiking, gardening (in a broader sense...maybe landscaping?), shooting, fishing, cooking, in rough order of time spent. It seems like I used to have a lot of time on my hands, even rebuilt old high-power microscopes for a while with the intent of getting into microphotography but never really did the latter.
Now that I live in the near tropics (and have small kids), it's more reading and fishing and staying out of the humidity. Years ago, I was a mean bridge player. @jpmcwjr 's post reminded me of that...might be a good way to beat the heat.