Spending time in Europe taught me many things. One of which is that American men are obsessed with denim. Everywhere you go it's jeans, jeans, jeans. Some guys only wear jeans, everyday.
Don't get me wrong, I love denim too...but wearing your heavy Japanese selvage denim in the heart of the sticky summer with sweat beading down your brow just doesn't make sense.
Invest in some lightweight cotton pants. Khakis, chinos, cotton trousers, whatever you want to call them. Not only do they breathe much better, but they give you a smarter summer casual look. Pick up (at least) one pair in a medium/dark shade of "khaki" and one pair in navy, these two go with just about anything. Depending on your level of boldness, you can wear pretty much any color you want. I wore my lime green pants ($8 at H&M) the other day and people loved 'em.
As a guide, keep them slim through the leg (tapered or straight), medium/low rise, and about 7-8" width across at the ankle (slim at the ankle is crucial!). Again, if your swagger is turned up enough (and your ankles caught some sun this summer), wear them rolled with no socks or get them hemmed a half inch above the back of your shoes.
The other good thing about switching to these pants, especially for denim lovers, is that it will spice up your relationship once the temperature creeps down in the fall and you and your favorite jeans can rekindle the old flame.
Yours in style, SB