In August, the weather in Newcastle upon Tyne is typically warm. Average daily high temperature in August is about 17 degrees above zero. On average, Newcastle upon Tyne has 18 rainy, 5 sunny, 5 partly cloudy, and 3 cloudy days in August. The rains are usually moderate. August as well as January, February, March, and June is considered the most uncomfortable time to visit Newcastle upon Tyne.