Linen is a light fabric that is typically worn during the summer when the temperature is much hotter, and heavier linens are usually worn during the colder months of the winter. Traditionally, lighter linens have been worn during the summer and woolly or heavier linens have been worn during the colder seasons, but now people are much more flexible with fashion conventions concerning linen clothes.
Today, people wear light, white linens during the winter as well, although they may end up layering them with other clothes because these fabrics have not been known to be very insulating. Conversely, people, especially those that work in air-conditioned offices, may end up wearing much heavier linen clothes because they are fashionable, despite the fact that the weather is very hot outside.
Some people take this fashion rule very seriously; however. It has been a traditional convention that people stop wearing white linens after Labor Day. However, modern fashion sense doesn't strictly prohibit this.