Originally Posted by MotoTex
Consider how often you find yourself riding for hundreds of miles in these conditions each year and make the appropriate choice for the lion's share of the riding conditions normally encountered.
Pretty much every weekend trip I take from june (hell, may now) to september has temps in the mid 90's +. They're all "hundreds" of miles.
On a 'strom, a calsci medium screen isn't enough windblock to make mesh work. If some mesh flows a lower amount of air it would probably be ok, but then it would be somewhat questionable from 80-90 degrees, compared to a vented solid jacket. When things are going right I can consume a bit less than a liter of water per 90 minutes in temps over 95. If I wear mesh I'll blow through almost two liters in that time, be drenched, and still feel thirsty and prematurely tired.
Everyone and every bike is different, but in the southeast we have entire weeks where mesh won't cut it in the lowlands, especially riding over blacktop.
I don't recommend mesh jackets to locals looking for something for hot weather. Of course, most locals would rather wear shorts and a t-shirt, so they don't ask all that often.
For 10-20 minute commute trips? Sure. Of course in the Southeast you'll be half damp before you even turn the key.