June in London is the rainiest month of the year. In June, the weather in London is typically warm. Average daily high temperature in June is about 18 degrees above zero. On average, London has 18 rainy, 6 sunny, 3 cloudy, and 3 partly cloudy days in June. The rains are usually moderate. June as well as January, February, March, and November is considered the most uncomfortable time to visit London.