May in Cotulla is the windiest month of the year. In May, the weather in Cotulla is typically hot. Average daily high temperature in May is about 31 degrees above zero. On average, Cotulla has 16 sunny, 8 partly cloudy, and 7 rainy days in May. The rains are usually heavy. May as well as June, July, August, and September is considered the most uncomfortable time to visit Cotulla.