July in Mililani is the sunniest month of the year. In July, the weather in Mililani is typically warm. Average daily high temperature in July is about 27 degrees above zero. On average, Mililani has 27 sunny, 3 partly cloudy, and 1 rainy day in July. The rains are usually light. July as well as January, May, June, and December is considered the most comfortable time to visit Mililani.