Live pollen levels and 5-day forecasts for cities across the US. Check before you head outside.
A pollen forecast predicts how much pollen will be in the air over the coming days, based on weather conditions, plant biology, and historical patterns. Levels are rated Low, Moderate, High, or Very High.
Pollen is typically released in the early morning and peaks between 5–10 AM, especially on warm, dry, and windy days. Rain washes pollen from the air, but counts rebound quickly on the next sunny day.
Spring (Feb–May): Tree pollen dominates — oak, birch, cedar, and alder are major triggers. Summer (May–Jul): Grass pollen peaks across the country. Fall (Aug–Oct): Ragweed is the primary allergen — one plant can release a billion grains per season.