Overalls. Farmers wear these because they are comfortable to wear while doing the labor that is required of a farmer. Overalls also stay up better than other clothes, which is essential because a farmer works in manure and dirt.
Keeping the overalls up will eliminate the farmer from having to be covered in them, protecting their skin and clothes underneath the overall. Another good reason for overalls is that it can hold the tools of the farmer, providing the farmer easy access to them when they need them. They can be worn at any time of year.