Well, it's Southern California. It's hot, dry, and smoggy, and there are almost never any clouds. Some people love this weather—some hate it. It certainly aids in achieving the coveted "year-long tan," which is something, but skin cancer is no picnic, and living in Los Angeles is commensurate to smoking a pack of cigarettes a day due to the air quality (or, more accurately, the lack of air quality). After a while, the weather can get monotonous, and during winter, it's just dry and clear all the time, but not even that warm, and because the Inland Empire is essentially a desert, it can get really cold at night. It doesn't snow, and it rains about once every few months. When it does rain, it pours. It's not unusual for the streets around Pomona to turn into raging rivers during a hard rain.
If you love rain and snow and wind and clouds and, well, weather, don't come to Pomona. You will be sad. Eventually, you may not notice the uniformly-bland lack of weather anymore, but you will still have a nagging feeling in your chest that something is missing. Many people express sorrow over not having seasons; Pomona really just has summer. Sometimes it's cold, but the leaves don't change, it doesn't rain, and the flowers are always in bloom. Some think of Pomona as the Garden of Eden. Silly people. According to my secular understanding of our creation myths, we were all cast out of there a long time ago. Plus, the Garden of Eden wasn't so smoggy that you couldn't see mountains that were only five miles away. Still, the ability to go to the pool nearly year long, or the beach, or out hiking, can be very appealing. As long as you don't find the smelly, dry heat too appalling, you'll have no problem adjusting to the weather.