December in Santa Ana is the windiest month of the year. In December, the weather in Santa Ana is typically hot. Average daily high temperature in December is about 31 degrees above zero. On average, Santa Ana has 26 rainy, 3 cloudy, 1 sunny, and 1 partly cloudy day in December. The rains are usually heavy. December as well as January, February, March, and April is considered the most uncomfortable time to visit Santa Ana.