I went to Puerto Ricos rain forest wearing this t-shirt. So of course the humidity was crazy high and it even rained for a while. What was really awesome about the t-shirt is that even when it rains you don't feel like it is wet. I later took a swim in a waterfall, and put on the t-shirt after i came up. Again it felt dry! So using this as you trek, run or work out is really comfortable. Really a great shirt and if you have a nice body - it will show it! It is not very forgiving if you don't haha!