July in Merlo is the coldest month of the year. In July, the weather in Merlo is typically warm. Average daily high temperature in July is about 14 degrees above zero. On average, Merlo has 13 sunny, 12 partly cloudy, 3 rainy, and 3 cloudy days in July. The rains are usually light. July as well as May is considered the most uncomfortable time to visit Merlo.