I have had this in the back of my mind since I saw a picture in a grade-school social-studies textbook, of a few children from various parts of North America, including Canada and Mexico. One was a boy about 8 or 9 wearing a long shirt that looked like a nightshirt, and a hat similar to a “coolie” hat (but without the pointed tip), or the wide-brimmed hat worn by Mercury, or even the “pith helmet” of explorers in Africa. Even at that time I sensed the kid was probably from a rural, possibly maritme part of Canada…am I close? And, in any case, what kind of climate is such garb designed to accommodate?
This what you’re looking for? 
Oh, you’re funny, Ethilrist. 
I’d imagine the average 8- or 9-year-old (in Canada or anywhere else) would be smarter than Gilligan… right back at you!
We pretty much wear the same clothes as in the U.S. (although we wear more Roots, hockey jerseys and toques in the winter), so I’ve no idea what you’re describing.
Unless the picture was a historical shot of a kid in a pea coat and outdated sailor hat from the 1800s or early 1900s as you can see here, but that kind of stuff hasn’t been really since the 1920s. A lot of those styles were influenced by UK styles.
Oh, I should note that the link above is a U.S. site. But, again in Canada we’ve always pretty much worn the same clothes as in the U.S.
I suspect that your textbook showed a picture of a Mennonite, who have a number of communities in Canada. They are similar (if not identical - sorry, don’t know) to the Amish in Pennsylvania.
I wasn’t able to find a picture of a Mennonite in traditional (for them, everyday) dress, but their hats are (for men, only to the best of my knowledge, and usually) plain, black and have a wide flat brim (much like the boater, shown in the link provided by Eats_Crayons).
The following is from an Amish site, which has a few pictures - and, perhaps, explains my difficulty in finding a sample!
Oo, I never thought of Mennonites. Probably because I’m so used to seeing the kids in standard straw boater hats that are more boxy than he described. But that sounds quite plausible too, esecially if the picutre was in a textbook.
And jiHymas they are very similar to the Amish, but not identical. Some Mennonites drive cars, have electricity etc. Amish do not. There was a good thread of the differences between the Amish and Mennonites a few months back if you’re interested.
The hat wasn’t a sou’wester, was it, dougie_monty?
What?? They have clothes in Canada?!
[scratches “Canada” off of “List of Places to Visit”]
Damn.
It could have been a sou’wester, Donkeyoatey. That’s why I suggested in the OP that the boy lived in a maritime area, perhaps Nova Scotia, Newfoundland, or such… 
Living in Nova Scotia, the only time I see anyone wearing a sou’wester anymore is when the tourists are taken on guided pub crawls.