In the northern part of Texas, the average temperature in January is around 40°F (4°C), while the average temperature in July is around 95°F (35°C). In the southern part of Texas, the average temperature in January is around 55°F (13°C), while the average temperature in July is around 100°F (38°C).
There are some exceptions to these general trends. For example, the Texas Panhandle can experience very cold weather in the winter, with average temperatures in January below freezing (0°C). Additionally, the coastal regions of Texas can experience milder winters, with average temperatures in January above 50°F (10°C).
Overall, the best time to visit Texas if you're looking for cooler weather is during the winter months (December-February). However, if you don't mind the heat, you can enjoy the state's many attractions during the warmer months (March-November).