July in Thurso is the warmest month of the year. In July, the weather in Thurso is typically warm. Average daily high temperature in July is about 14 degrees above zero. On average, Thurso has 24 rainy, 4 sunny, 2 cloudy, and 1 partly cloudy day in July. The rains are usually moderate. July as well as January, February, March, and April is considered the most uncomfortable time to visit Thurso.