Looks like a stocking. I don't think Germany is the best example as it's not exactly a hot and humid climate.
Yes, it is a stocking, as the colour is whiter than the man's skin. It still gets quite hot during August, even in Germany, to my knowledge.
There is another article from the same website that discusses appropriate attire for different types of work, and it features traditional pictures from different cultures throughout the world. At the bottom, it shows a man working as a farmer in Mexico, which has a hot and humid climate.
https://www.traditioninaction.org/Cultural/C073_Work.htm