I hope you're staying warm in this unusually cold weather. Some frost in winter isn't unusual here in the hills, nor is a bit of snow every once in a while. But this has been cold and not warmed up much during the day. Our birdbath froze solid over night, and only thawed around 2PM or so. It's on its way to freezing again tonight, so spare a thought and more if you can for those who have less shelter than you.
Apparently (but alas, not surprisingly) it's cold in Oakland's classrooms, too.
And City Homestead has some good info for caring for your plants and house in cold weather. Frozen pipes are not out of the realm of possibility if this cold sticks around. It should warm up some when the next storm comes through...I hope!