Karen, I'm not certain about our winter low temps. It's highly variable. One obeservation is that I'm in the same USDA zone as you are, so I ought to be able to grow most of the cactus that you do, at least from a cold hardniness standpoint. Another is that it rarely gets to, say, 10F at night without warming up ten or twenty degrees the next day.
Our summers, I think, are coolish. It's a very rare day that gets above 100F. And I'd say most summer days don't make it to 92F. Lots of cool nights. I have trouble growing tomatoes here, which I attribute to the coolness. This year I'm trying a number of short-season tomatoes since they are bred for cooler summer weather. One other comment: we average about 20 inches of rain per year, so cacti that cannot stand a little dampness in December and then again in August will not do well. I do have a striped yucca or two that are very young and not doing well.
Linda, thanks for the kind comments. I love being outside in the garden and I'm always happy to see the blooms arrive this time of year. Sharing them really adds to the joy.