Weather will likely play an important role when you plan your trip to Santa Maria, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually January and December with an average temp of 73°F, while the coldest months are July and June with an average of 56°F. The rainiest months in Santa Maria are January, February, December, and March, with each month seeing an average of 7 inches of rainfall.