May in Tarragona is the cloudiest month of the year. In May, the weather in Tarragona is typically warm. Average daily high temperature in May is about 23 degrees above zero. On average, Tarragona has 13 sunny, 8 rainy, 8 partly cloudy, and 2 cloudy days in May. The rains are usually moderate. May as well as June, July, and October is considered the most comfortable time to visit Tarragona.