For American travelers suffering from hay fever, choosing the right European destination this summer is crucial. New research from Hellotickets reveals the worst cities for pollen allergies. Zurich tops the list for early summer, while Milan and Athens are particularly problematic in July and August. Dr. Claire Merrifield, GP and medical director at Selph, emphasizes the importance of researching pollen counts and preparing for symptoms to ensure a more enjoyable travel experience.