December in Belton is the cloudiest month of the year. In December, the weather in Belton is typically warm. Average daily high temperature in December is about 14 degrees above zero. On average, Belton has 12 partly cloudy, 10 sunny, 5 rainy, and 4 cloudy days in December. The rains are usually light. December as well as January, May, June, and July is considered the most uncomfortable time to visit Belton.