An allergy is an abnormal response to a protein and people can respond abnormally to about any kind of protein. Some of the common allergen proteins are pollen, dander, cockroach, pets, molds, mildew and even foods. A lot of people get confused between an allergy and a cold since their symptoms are almost the same. If it happens regularly and in a patterned way every season, then it could be an allergy or rather a seasonal allergy.
Some of the most symptoms of seasonal allergies include sneezing, itching, congestion, drainage, pressure near the nasal areas etc. Itching is one of the symptoms which make allergies different from cold. Seasonal allergies are basically the allergies which come and go with seasons. When trees are secreting pollens then most people tend to suffer from allergies which can be pollen allergies.
In the summer season, people get grass allergic to the grass pollen whereas in the winter season, there are other kinds of allergens that may cause allergies. So if you get allergic only in one particular season, then you may be suffering from a seasonal allergy which may go once the season is over.