Airborne pollens and mold spores lead to seasonal allergies (hay fever) in people who are allergic to them. There are three main groups of pollens; these vary by season. First, the trees begin to pollenate in the late-winter and early spring. Then, in mid- to late-spring, the grasses start pollenating. Grass pollen levels peak initially in early summer and then again in late summer and fall. Weeds mainly pollenate in the late summer and fall, but there is often a little weed pollen in the late spring and early summer.

​Many people with allergy problems have more trouble during times of the year when different pollen types overlap. For example, during the late-spring, tree and grass pollens tend to overlap. Also, in the late summer and fall, grass and weed pollens are present together. To make matters worse, mold spores are also present, blowing in the outdoor air at the same times we are exposed to plant pollens.

We are now entering a time of year with high levels of both grass and weed pollens. In spite of the large amounts of pollens present, most people can have very good relief of their allergy problems with the right treatment plan, tailored to their specific needs. If you are having trouble with your allergy or asthma problems, please talk to your primary care doctor or to an allergist.