They are made year-round, of course, but are particularly prominent in December.
From the excellent NPR story (with lovely photos) Tamales for Christmas Are A True Texas Tradition:
“The corn masa-and-meat bundles — individually wrapped in corn husks and then steamed — are part of the traditional Mexican celebration of las posadas, which commemorates Mary and Joseph’s search for shelter before the birth of Jesus.”
Every town has its favorite local places to pick up your order (for those who don’t throw a tamalada tamale-making party themselves) but I wanted to mention a year-round Texas Hill Country tamale and Tex-Mex food restaurant between Llano and Burnet, next to scenic Lake Buchanan – the Tamale King.
I love that on their business card under the highway address, it says, “Next to Phillip’s Chevron.”
My parents, who have lived in the area for decades, tell me that the owners started out under a nearby tree, selling tamales and other items out of a portable cooler. Years ago they bought property, built a restaurant and are still expanding.
The menu is extensive and well-priced, the decor is colorful and the delicious tamales are $12/dozen. Not cheap, but not bad for handmade, served at one of the few non-fast-food joints in the area and one of the few Tex-Mex restaurants as well. You can get them To Go; there were a bunch of people running in to do just that on the day I visited.
The well-regarded Canyon of the Eagles Lodge and Nature Park is nearby as well, if you’d like to stick around after eating all of those tamales.