December in Tyler is the rainiest and the cloudiest month of the year. In December, the weather in Tyler is typically warm. Average daily high temperature in December is about 12 degrees above zero. On average, Tyler has 9 sunny, 8 rainy, 7 cloudy, and 7 partly cloudy days in December. The rains are usually moderate. December as well as January and February is considered the most uncomfortable time to visit Tyler.