May in Buenos Aires is the rainiest and the cloudiest month of the year. In May, the weather in Buenos Aires is typically warm. Average daily high temperature in May is about 17 degrees above zero. On average, Buenos Aires has 12 sunny, 12 partly cloudy, 6 rainy, and 1 cloudy day in May. The rains are usually moderate. May as well as June, July, and September is considered the most uncomfortable time to visit Buenos Aires.