Do you have any kind of barn or shed? Greenhouse?
How cold does it get there?
It drops from Zone 8 along the coast down to about Z 6 in the mountains.
Heat/humidity can be brutal in the warm months, regardless of the 'hardiness' zones.
Your worms will do best if you can keep them within a range of about 55* to 80*.
If they are to be kept outdoors, year round, you will need to provide shade (and air circulation) in the warm months. Perhaps, the north side of the house, and some straw bales. The straw bales could also be used in the cold months, but the worms should now be on the sunnier south side of the house.
Another possibility would be to harvest the young ones in autumn, and bring them indoors for the winter, where they can produce many more young ones for the spring.
Ronnie Ugulano wrote:I'm in zone 9, but all of my bins are outdoors. We get temperatures from about 29*F to 105*F over the course of the year - snow only every 20 years or so. My bins are under the eaves on the N side of the house, which is in the shade all year round. Winter is actually my better growing time, because there's usually more moisture and cooler temperatures. I've never had problems with the bins freezing. The bins do produce some of their own heat. When it gets hot, the moisture helps to keep the bin temperatures moderated.
I second what Ronnie says. I'm zone 9b with temps similar to what he stated (although the colder end of that range is rare and short-lived and the snow is never). Worms tolerate temperatures much higher than their ideal temperature. Their activity slows down in the summer, but it's okay because that's when the black soldier fly larvae become active (they migrated in naturally for me). Just keep them in a shady spot and make sure they don't dry out.
All I can say about the cold weather is that their activity also slows down when temps are in the 40s or 30s - I don't know beyond that, but others have given some good suggestions.