You can prune them now, if you like. Because the weather is cooler at this time of year, they probably wont resprout till warmer weather in January. Even so, in your zone you may not get much frost damage and if you do, the frost may just disfigure the foliage and not kill the plant. Disfigured foliage can be removed anytime after it occurs. In many years we get a freeze around the 20th of December and again towards the end of February.

I would prune them in end of January or up to first week of March depending on the weather. There are many warm spells that occur in Winter that could resprout the roses prematurely if you prune them now. The resprouting followed by the rainy winter days could spell mildew and rust the entire next year. When I know for sure the rains wouldn't be too much in the next ten days in late winter, that's the time I would prune them, not leaving any leaf and spray with fungicides after the pruning. Then I enjoy disease free roses the rest of the year until the rainy season hits again.

You get frost down there? Please. I know the weather is changing all over, but that is rare, surely. You can prune now, and if you are worried about any disease and rust, put some systemic rose food down when the flowering period approaches. Generally speaking, I would wait until December. You don't have long; but in CA you have many options on pruning. You could trim the legginess off right now if it bothers you (light shaping) and then do a harder prune in January.

hopflower, frost is quite common in some areas especially inland or in the foothills.
I get it every year and more than once.
During the freeze last year my small water feature with pond had 1/4 inch ice for a week.

For the past few years I've followed the method Joereal laid out and been much happier than with previous early pruning. Its not the frost alone, its the inevitable week of 80 degree weather in Jan followed by a 25 degree night in February here in L.A. that makes me wait and fully remove all foilage.

I don't love winter pruning my roses so much that I want to do it twice.

I have been pruning roses in Riverside (SS 18) for almost 30 years. I've pruned Hybrid Teas as early as the weekend after Thanksgiving. The most damage that occurred was some tip burn and some puckering of the leaves on roses that had resprouted before the end of December. Most didn't resprout until mid January. There was a 15 year period where Riverside never had frost or freezing temps. This year the coldest was one night of 26 degrees F. Many sub-tropicals experienced leaf and upper branch tip die-back. The roses didn't have any damage, but that could be the result of micro-climates , as well. Roses are very tough plants and will recover rapidly from damage. With only 1.98 inches of rain per year, this past year, and the dryness continues, we don't worry about disease problems. Spraying with a dormant oil helps to prevent many over-wintering disease problems. I once cut a Simplicity rose hedge back in early November so that it would be blooming for a christmas party. Worked okay, not heavy with blooms but still satisfactory.
Hopflower, since you like bulb flowers, have you grown any Geissorhiza. If so, how did they perform?

Most roses are as cold hardy as apples. Some can survive USDA zone 5 conditions, so I am wondering why we even need to worry about frosts or record breaking cold spell of California. They can take on record breaking cold spell each day the entire winter and would okay come spring provided you prune them. The only thing perhaps to worry about is the moisture when the frosty icing melts and could bring in the diseases.

Perhaps there is a different context of worrying about the frost and would like to be enlightened.

No kidding. I live in northern CA where we ALWAYS get a bit of frost and no problems; and I too have been growing roses for many years. I have had some frost damage at certain times, but nothing near major.

goldenginko: No, I am a bulb fan but have not grown them all, I am afraid. I generally like the major ones and am not so much into the little minor types although they can be interesting. This year I am trying a gloriosa rothschildiana, though.

Here is a link if you are interested in Geissorhiza and have not seen it. Have you tried them?

Here is a link that might be useful: Pacific Bulb Society

No, but saw them on this site and thought they were very pretty.
http://images.google.com/imgres?imgurl=http://capeseedandbulb.com/okamiesb.jpg&imgrefurl=http://capeseedandbulb.com/flowerlist.html&h=400&w=319&sz=108&hl=en&start=2&sig2=riQceOAISmaTQEkOiaVHQg&tbnid=dGBkHZ1dy9JF8M:&tbnh=124&tbnw=99&ei=-sjFRoD3LqCQggPe5sW6Bg&prev=/images%3Fq%3DFerraria%2Bkamiesbergensis%26gbv%3D2%26svnum%3D10%26hl%3Den%26sa%3DG

Thanks for all your responses everyone. I know it's hard to believe that we get frost down here, but I regularly wake up to a frosted white roof during the winter, and a few times a month I have to get the credit card out in the morning to scrape off my windshield. I've decided to take a staggered approach to my rose pruning this winter - I'll start with the leggiest offenders this week and slowly work through the rest up until New Year, which is my usual pruning time. That way it'll be easier on my forearms too - time for the scars to heal between pruning sessions!

Happy gardening.
Provence

1 microsecond after midnight, any day of the year?

Actually, once we have a frost, the sap is down and so the plant is protected quite a bit. If you want to prune the really leggy stuff off, you can do it anytime. Hard pruning might wait until danger of a real long frost period is over. It is doubtful your rose would die from anything down where you are however; maybe a little frost damage, but nothing spectacularly dangeous would occur.