breathable cap/hat?

Watch out for too large a brim that could interfere with your pack. Common sense and personal preference round out the criteria.

I like the Outdoor Research caps.  I have several of the OR Swift caps (perfect fit for me) and I also have one of their Sun Runner caps which is essentially a Swift cap with a removable cape for when you really want to dodge the sun (covers the back of your neck and side of your face).  Nice that the cape on the Sun Runner is so easily removed.

+1 on the Sun Runner Cap.  Light. Adjustable fit. The removable skirt is great for evenings and when you’re out of the sun.

Do you want full sun coverage?  I don’t like the Sun Runner Cap – it just doesn’t fit right on me and I hate to have the skirt around my head.  Maybe if I was in a desert and needed sideways coverage, that would be the best option…

For multi-night trips, I just take my trusty old OR sombrero.  Full sun coverage, still waterproof after 20 years, drawstring to keep it from blowing away above treeline, rear brim just folds smoothly down if I’m wearing a tall pack, doesn’t get too smelly, it doesn’t breath well but that can be nice when I need a little warmth for my bald head.

For day hikes, unless it’s definitely going to rain, I like to use light running caps, whatever is cheap that fits well, feels super-breathable, and has UPF50 coverage.  I have to test out which one feels best on my head. Some are too shallow, too deep, too wide without excessive tightening, weird brim shape, uncomfortable seams, etc….  But I don’t know how people use them when it’s sunny on top of a super-windy ridge.  A simple buff is probably the way to go for these conditions.

When I wear a hat it is usually a Tilley Airflow (expensive) or sometimes an eVent ball cap I bought at REI. All in all, they really aren’t much better than the cheap GI Boonie hat I wore for decades.

Columbia coolhead hats look very casual. Carry an appropriately sized rag and small clips to mimic the sunrunner hat.

I wear an OR Swift and love it. And if you google it just like that, you will get all hits for Taylor Swift. Just a heads up. lol

http://www.outdoorresearch.com/en/sombriolet-sun-hat.html

I have fair skin and recently picked up the OR Sumbriolet and am very happy with it. Has more sun coverage than my surplus boonie hat, is more comfortable, and breathes a lot better. Despite the large brim, the proportions and curve look “normal.” In other words, it doesn’t look completely ridiculous.

Truckers hats have mesh on the back, so the trick is to find one without the usual foam front (which is too warm IMO). I use the OR Big Rig, which has a Jute front panel. A friend of mine has one from John Deere that’s plastic mesh all the way around, which would be even better.

If you need more sun protection for your neck and ears, just tuck a bandana under it. No need for an expensive and goofy-looking thing with a neck flap built in.