May in Edinburgh is the sunniest month of the year. In May, the weather in Edinburgh is typically warm. Average daily high temperature in May is about 12 degrees above zero. On average, Edinburgh has 19 rainy, 6 cloudy, 5 sunny, and 1 partly cloudy day in May. The rains are usually moderate. May as well as January, February, March, and April is considered the most uncomfortable time to visit Edinburgh.