April in Oakland is the cloudiest month of the year. In April, the weather in Oakland is typically warm. Average daily high temperature in April is about 15 degrees above zero. On average, Oakland has 12 rainy, 9 partly cloudy, 8 sunny, and 1 cloudy day in April. The rains are usually heavy. April as well as January, February, March, and November is considered the most uncomfortable time to visit Oakland.