For the mild brow-mopping misery that is wearing a suit in the middle of the summer, I have a lot more options today than I did when I first started wearing suits. It’s now relatively easy to find off the rack suits in linen or summer weight wool or blends, in plain weaves or patterns, buggy lined or not at all, to help with the heat.
When I was younger I felt like I had two options, both pretty “trad”: seersucker or cotton poplin. I still wear the seersucker suit I picked up 5 or 6 years ago a couple of times a summer (oddly, it seems to have shrunk), but I’m currently shopping for something I didn’t realize was hard to find until I started looking (isn’t that always the way, though): an olive cotton summer sack suit. Intended to to be worn in the ideal way: with a navy on white fine stripe broadcloth shirt and a Brooks Brothers #1 repp in burgundy, gold, and navy. Khaki cotton suits are fine; navy cotton I don’t much care for; olive, even a khaki-toned, taupe-ish olive, is the right hue for me.
I admit to some nostalgia re: olive cotton suits, which were a favorite of my favorite college professor, and which I routinely found in thrift shops growing up in the Mid-Atlantic. Usually part polyester, to ease wrinkles, and not nearly as cool wearing as you’d expect a summer suit to be, just summer appropriate by virtue of being not wool flannel. I like olive cotton paired with other American classics: button down collars (yellow oxford is an interesting choice, although pinpoint might be better for summer; ecru can work, too), rep stripe or Irish poplin ties, engine-turned belt buckles, penny loafers.
I thought this would be easy to find–Brooks Brothers always has them. Incorrect! Well, J. Press, then. Nope. Haspel, then, makers of the workhorse American summer suit. Not this year (but–lavender seersucker?!). Not even Ben Silver! Chipp would. Of the major trad/prep shops, only O’Connell’s comes through right now. Fortunately, there are usually some on ebay or etsy. This year I’ve also seen beautiful, more worldly versions from Sartoria Formosa and Ring Jacket , although obviously not in quite the same traditional sack suit cut.
The Armoury’s Mark Cho in an olive cotton suit from Ring Jacket.
O’Connell’s version has the right sack suit details–100% cotton.
I’ve owned vintage versions of the classic wash-and-wear Brooks Brothers suit–never actually tossed one in the wash, though.
Ring Jacket at Supply and Advise. 
Sartoria Formosa at No Man Walks Alone.
Lead image via Heavy Tweed Jacket.