New Haven, CT Pollen Levels Today

New Haven, Connecticut sits along Long Island Sound in a humid continental climate zone, where a mix of coastal moisture, dense hardwood forests, and distinct seasons creates a prolonged and varied allergy season stretching from early spring through the first hard frost.

Tree pollen is typically the first major trigger, emerging in late March and peaking in April and May, with oak, maple, birch, cedar, hickory, and sycamore being especially prevalent throughout the city's neighborhoods and surrounding woodlands.

As tree counts taper, grass pollen takes over from mid-May into July, driven largely by timothy, Kentucky bluegrass, orchard grass, and ryegrass common to lawns and open fields. The late-spring overlap between lingering tree pollen and rising grass counts often intensifies symptoms for multi-sensitive individuals.

By mid-August, weed pollen dominates, with ragweed being the primary offender through the first frost in October, alongside lamb's quarters, pigweed, and plantain.

Beyond pollen, New Haven's proximity to the coast and humid summers promote persistent outdoor and indoor mold, particularly in damp basements and after heavy rainfall, while vehicle-related air pollution along I-95 can aggravate symptoms.

Overall, New Haven's allergy profile is defined by a long, overlapping season marked by diverse hardwood pollen, heavy ragweed, and moisture-driven mold.