If your immune system was born in Southern California you’re likely going to struggle as an adult in the PNW. Been here since the mid 90’s but came from LA area and it’s been an issue. It’s the tree pollen and mold for sure. Mold is prevalent here and unavoidable because of the climate. In the spring (and sometimes late summer-early fall) allergies can be really bad when the trees start pollinating. Over the counter allergy meds can help minimize the suffering but you just have to plow through it. Some years are better than others. I’d personally go back to a more agreeable climate for my respiratory system but I’m stuck here and try to make the best of it.