January in Fort Worth is the coldest month of the year. In January, the weather in Fort Worth is typically warm. Average daily high temperature in January is about 12 degrees above zero. On average, Fort Worth has 19 sunny, 9 partly cloudy, 2 rainy, and 1 cloudy day in January. The rains are usually heavy. January as well as February, June, July, and August is considered the most uncomfortable time to visit Fort Worth.