August in Lerwick is the warmest month of the year. In August, the weather in Lerwick is typically warm. Average daily high temperature in August is about 13 degrees above zero. On average, Lerwick has 14 rainy, 11 partly cloudy, 4 cloudy, and 2 sunny days in August. The rains are usually heavy. August as well as January, February, March, and April is considered the most uncomfortable time to visit Lerwick.