If you want mold resistance you have to give up bud density. Simple as that. Afghans tend to do bad outdoors, unless they have been specifically selected for fluffier buds. If the buds are too hard, they soak up water like a sponge and hold it close to the stems. The few minutes of sunshine and breeze each day aren't enough to dry it out so the buds are chronically damp. I suggest growing some of the LBH sativas. Or an old school 50/50 skunk with some fluff. The trade in extended flowering time is a gamble I'd be willing to take, especially in you microclimate which hardly frosts because of the ocean around you.
The problem is most medical strains are bred indoors. Fluffy buds are undesirable because the same size plant with same sized buds yeilds less. These indoor bred strains have water applied directly to their roots and the buds never get wet, even for 10 generations of more of breeding. The abnormally hard, dense buds are selected because they yeild more, but in reality they are a mutation that would never survive in the wild.
Do some looking through strains specifically bred for outdoors. Cres has good short finishing gear that was bred for Canada, where the rain isn't as chronic, but they will probably do good in your climate. Just stay as far from indoor afghan as you can.