Tiefencastel had a population (as of 2013) of 254. , 15.7% of the population was made up of foreign nationals. Over the last 10 years the population has decreased at a rate of -2.2%. Most of the population () speaks German (58.3%), with Romansh being second most common language (37.8%) and Italian the third ( 1.3%). The age distribution, , in Tiefencastel is; 37 people or 16.1% of the population are between 0 and 9 years old. 16 people or 7.0% are 10 to 14, and 8 people or 3.5% are 15 to 19. Of the adult population, 23 people or 10.0% of the population are between 20 and 29 years old. 36 people or 15.7% are 30 to 39, 36 people or 15.7% are 40 to 49, and 27 people or 11.7% are 50 to 59. The senior population distribution is 25 people or 10.9% of the population are between 60 and 69 years old, 15 people or 6.5% are 70 to 79, there are 6 people or 2.6% who are 80 to 89, and there are 1 people or 0.4% who are 90 to 99. In the
2007 federal election the most popular party was the
CVP which received 42.5% of the vote. The next three most popular parties were the
SVP (30.9%), the
SPS (13.6%) and the
FDP (12.8%). ==Climate==