Fall is primarily weed pollen season with grass pollen tapering off in late summer. Airborne molds also contribute to fall symptoms. The major fall pollen is ragweed which begins pollinating in North Carolina during August and peaks in September continuing to cause symptoms in October and the first part of November.

Ragweed has inconspicuous small pale yellow-to-greenish flowers (often confused with goldenrod which has bright yellow flowers) and is found in abundance on roadsides, fields, pastures, and in some cultivated yards or parks. Ragweed pollen is abundant, potent, lightweight - which makes it easily airborne, and is inhaled into the nose and deep into the lungs. 

It can cause the same allergic rhinitis (commonly called hay fever) symptoms in the eyes and nose triggered by spring pollens. Pollen-allergic asthma sufferers also can have increased symptoms from ragweed exposure.