Oregon's Willamette Valley is one of the highest grass seed production areas in the world, making it a notorious allergy hotspot. Eugene regularly sees extremely high grass pollen counts.
Peak pollen season in Oregon: March–June. Primary allergens: AlderBirchGrass
Tree pollen is the first major allergen each year in Oregon, typically starting in early spring with cedar and alder, followed by oak and birch through May.
Grass pollen takes over in late spring through early summer, peaking from May to July depending on location within the state.
The pollen count in Oregon varies by city and season. Peak pollen season runs March–June. Select a city above for live data.
Pollen levels vary across Oregon. Cities in warmer, more humid areas typically see higher counts. Check individual city pages for current levels.
Pollen season in Oregon peaks in March–June. Tree and grass pollen are the main seasonal allergens.