San Mateo Ixtatán is a municipality in the Guatemalan department of Huehuetenango. It is situated at 2,540 metres above sea level in the Cuchumatanes mountain range and covers 560 square kilometres of terrain. It has a cold climate and is located in a cloud forest. The temperature fluctuates between 0.5 and 20 °C. The coldest months are from November to January and the warmest months are April and May. The town has a population of about 10,000, and is the municipal center for an additional 20,000 people living in the surrounding mountain villages. It has a weekly market on Thursday and Sunday. The annual town festival takes place from September 19 to September 21 honoring their patron Saint Matthew. The residents of San Mateo belong to the Chuj Maya ethnic group and speak the Mayan Chuj language, not to be confused with Chuj baths, or wood fired steam rooms that are common throughout the central and western highlands.