Between early June and early November, we typically don't get any measurable rainfall. The central valleys heat up, the air rises, and is replaced by the cooler, denser air from the Pacific Ocean at San Francisco Bay. This climatic condition commonly results in strong afternoon winds which put a lot of dust in the air.

While this dust is annoying, it makes for some pretty spectacular colors at sunset, each day being slightly different, but colorful nonetheless. What is a pain to the sinuses can be a pleasure to the eyes.