A quick search reveals your chances of success.

Here is a link that might be useful: Search: growing papaya from seed zone 9 california

The answer is ..no.
BUT! If you are determined,you can try growing them in the hot sun all summer,then build some kind of coldframe around them,add a small heater. I have read of that being done in the valley. As I recall,he did get ripe fruit. But I think the effort and heating costs was a one year effort.
And as another post about this jogged my memory,he had TR Hovey papayas. Hard to find.

Thanks mrclint for the link and stanofh I do have a tr hovey also that I got for a cheap price that was very reasonable. I got it from Florida hill nursery for $6.99+shipping. As I understand it was quite hard to get one of these baby when they first were release, but now a lot of nursery carries them. I've also seen them at quite a bit higher price on logees site for about 3x as much, but not sure how big their plant they offer are. Mine was about 12 inches. I don't think I'm going to cover up and just see how they do and if I only get green ones before winter comes, I could just make green papaya salad...yummy(mouth watering). If you might want to try your hands at one for a reasonable price I suggest Florida Hill Nursery or Well Spring Nursery.

This year in Fresno -they are STILL ALIVE??. They took mid 20's??
wow.

Sorry for the confusion stanoh, You might have confuse me with the other guys you were trying to remember with the heat protection in your earlier post. Mine that I mention is still alive and doing well since I haven't planted it in ground yet and still in a pot. Btw i'm the guy who is the op(original poster) of the question. Yup that would definitely be a wowzer if the papaya did get that cold hardy. What I meant was if I do actually get fruit with in the same year as planting and only get unripe papaya by the time winter hit, then i will just make green papaya from those green ones. Sorry to have confuse you Stan.

These guys do grow in the valley. They will tolerate the cold with a proper microclimate. They won’t survive in an open air environment. Even with dieback on the top (like banana) they will continue to grow. Mature papaya (1 year plus) can even survive the winter with fruit. For proper growing conditions you can view Growing tropicals in Phoenix az, which has the same climate as the cv.

Btw- there is a vid on youtube by vegan athlete of comparing Papaya's in hot,hot,Phoenix. As I recall,Maridol were slowest and shortest over a years time or so ( Same for me in Hayward,Maridol took three years to reach 4'..then rotted in a rainy winter with larger fruit on it. Just not large enough to eat ripe.) And some type he called by its "official" name like ES 32 ( I cant recall exactly) that grew to 20' in two years and had lots of fruit. THAT one is also known as TR Hovey.

I wouldn't count on the same in the valley or bay area..but worth a try if we have a sunny winter and the usual keep frost off it care.

Phoenix has the same winter lows as Fresno. It’s a pretty similar comparison for zone suitability

Phoenix days average about 10f warmer in winter and much more sun. But,Fresno is worth a try- you got the heat and if you keep 32f off the plant,give it a try. I have been told that TS Harvey and even a Red Caribbean Papaya are better in non tropical climates.