June in Brownsville is the sunniest month of the year. In June, the weather in Brownsville is typically hot. Average daily high temperature in June is about 33 degrees above zero. On average, Brownsville has 16 sunny, 11 rainy, and 3 partly cloudy days in June. The rains are usually moderate. June as well as July, August, and September is considered the most uncomfortable time to visit Brownsville.