Since the forests are opening back up because of the rain, now is a good time to ride the Arrowhead/Big Bear area.
The cooler temps right now also make all the desert areas great: El Mirage, Lucerne Valley, the Barstow area, Dumont Dunes, Jawbone Canyon, (there will be a big DRN ride there the week of Thanksgiving!), Ocatillo, etc. There are also a number of trails in the mountains between Agua Dulce and Palmdale, but they may still be closed right now due to recent fires. Check the SoCal Wrecking crew forum to hook up with some great guys for some local rides!