Dutch said:If you are "working" in the outdoors, nothing will perform as well as natural fibers. Wool, cotton, canvas, and leather...
Or, you can combine the advantages of both. RedHead, ****ey, Carhartt, etc. now offer cotton duck work coats and pants with GoreTex, or similar, linings for waterproofness.
Don't own any of this waterproof work clothing myself, but have seen it in catalogs. Fairly expensive, but maybe worthwhile if you do hard work outside in the rain very often.
I've owned cotton duck work jackets by ****ey and Carhartt, and used them many times while cutting wood and clearing brush. Their heavy cotton duck fabric stands up to abuse quite well.