When the dress code is business casual but the forecast warns of oppressive heat, the right choice is a blazer made of summer-weight fabric. The material should be lightweight and breathable, with the top candidates being linen, cotton, silk and lightweight wool. The blazer should also be unlined — a style that cuts unnecessary weight and softens the silhouette for a more causal aesthetic. Summer-weight blazers work well with everything from chinos and a tie to jeans and a t-shirt. (But wait. Are ties actually toast?) With proper preparation for the upcoming heat, you can stay cool without sacrificing style.
Best Overall Summer-Weight Blazer: Buck Mason Carry-On Jacket
Buck Mason's relaxed-fit Carry-On Jacket — aka a blazer — is cut from lightweight stretch cotton (97-percent cotton, 3-percent spandex). Stretch let the designers ditch the back vent (and the excess fabric needed for one); patch pockets without flaps shed weight; and opting for no cuff buttons makes this option even more casual. Overall, it's a winner worth wearing to every semi-formal summer event.
Best Upgrade Summer-Weight Blazer: Natural Large Herringbone Linen-Silk Jacket
Made in Italy from a blend of 82-percent linen and 18-percent silk, this herringbone Drake's blazer works well in both summer and winter. The texture and tailored fit (with emphasized yet natural shoulders) add interest, while the unlined interior sheds weight. The patch and breast pockets that populate the front skew traditional, but this jacket would work as well with white jeans as it would matching trousers.
Best Affordable Summer-Weight Blazer: Everlane The Casual Blazer
This option is so simple that it pairs well with nearly anything else. White, black, navy blue, brown, even gray! Dress it up — if you must — with loafers and trousers or pair it with jeans and sneakers. It's versatile without needing to be advertised as such, if that makes sense.
J. Crew Wallace & Barnes Cotton-Linen Chore Blazer
The clothing released under J. Crew's Wallace & Barnes lines oftentimes outshines the standard-issue stuff. This cotton-linen chore blazer is no exception. It's unstructured yet flattering, simple yet statement-making and appropriate in both the middle of summer and the first few weeks of fall.
Todd Snyder Italian Seersucker Sport Coat
There are ways to wear a seersucker blazer without looking horse race-bound. Picking an iteration with a bit more flair — like this Todd Snyder option — is one way of doing it. It's tailored, comes in what they call an "Italian fit" (order one size up) and the lapel is skinnier and shorter.
Bonobos Unconstructed Italian Linen Blazer
Just because trying to stay cool doesn't mean you can't look cool, too. An unconstructed blazer adorned with a pattern can trick the eye into seeing lines where there aren't — simply put: it'll look more put together than it actually is. Bonobo's linen blazer, which is cut from breathable Italian fabric, is proof! For being both lightweight and unlined, it appears all there without extra weight.
Alex Mill Mercer Blazer
Alex Mill's Mercer blazer blends several different styles into one unique coat. Part-chore coat, part-shawl collar jacket, part-blazer, it's lightweight without being shirt-like, knit a bit thicker and casual while still being incredibly cool. If I had a reason to dress up every day beyond banal errands, this would be my go-to ensemble.
Corridor Linen Indigo Ticking Stripe Blazer
Corridor's popular casual blazer is constructed in India from Indigo-dyed linen. (Say "in India from Indigo-dyed linen" three times fast.) The ticking stripe proves reminiscent of seersucker but with less pile, and button-closure patch pockets spotlight heavy outerwear influences.
Drake's Ecru Cotton-Linen Games Blazer Mk. II
It's hard not to look at Drake's cotton-linen Games Blazer and not role-play a bit. It's a bit Country Club bad boy; part rebellious Royal. (Ignore me.) Made in Italy from a 60-40 blend of cotton to linen, the blazer is unlined and unstructured, features five pockets and a bespoke lapel shape.
Todd Snyder Italian Wool Hopsack Sportcoat
Surprisingly, as it's oft used for beanies, socks and sweaters, wool works well in summer, too. Wool hopsack, specifically, because it is basket woven, proves breathable enough to beat even the most smoldering summer days — even this black Todd Snyder option will keep you cool.