I've got 8-yard kilts in each weight. I grew up in the South were it gets really hot and humid in the summer, so I found that the weight not necessarily an issue for the heat. Instead, the colors were the thing. The darker colors soak up more sunlight and are hotter than lighter or brighter colors. So my 16 oz was a little cooler than my 13 oz, because the 16 was a lighter color and soaked up less heat. Of course, my 11 oz is the coolest, but is also the lightest.