In May, the weather in Cabo de Santo Agostinho is typically warm. Average daily high temperature in May is about 27 degrees above zero. On average, Cabo de Santo Agostinho has 25 rainy, 4 partly cloudy, and 2 sunny days in May. The rains are usually heavy. May as well as January, February, March, and April is considered the most uncomfortable time to visit Cabo de Santo Agostinho.