Seasonal allergies are allergic responses of your respiratory system to breathing in pollens that are given off by trees, grasses and weeds. Pollens, which look like microscopic balloons float great distances in the wind. Mold spores can also cause seasonal symptoms usually in the late summer and fall.
Typical season allergy patterns:
- Tree pollen is usually in the air from March to June.
- Grasses start to pollinate and give off pollen into the air in early June and continue into the summer.
- Weeds give off pollen in the late summer and early fall, when outdoor mold can also be a problem.
Because plants and trees that cause allergy depend on the wind for pollination rather than insects, they often give off pollen that is both colorless and odorless.