Seasonal allergies (hay fever or allergic rhinitis) occur when your immune system overreacts to airborne irritants like plant pollen and mold spores. Symptoms typically include sneezing, congestion, and itchy, watery eyes. The most effective management strategies combine environmental avoidance, over-the-counter (OTC) medications, and monitoring. Common Triggers & Timeline Allergy season generally follows a seasonal cycle depending on your local climate and specific geographic location: Spring: Tree pollen (e.g., birch, cedar, oak). Summer: Grass pollen. Fall ...