May in Shediac is the rainiest month of the year. In May, the weather in Shediac is typically warm. Average daily high temperature in May is about 13 degrees above zero. On average, Shediac has 18 rainy, 8 cloudy, 4 sunny, and 1 partly cloudy day in May. The rains are usually moderate. May as well as April, June, November, and December is considered the most uncomfortable time to visit Shediac.