Generally, allergies last longer than a cold, often for a few weeks. If you notice a pattern in which you suffer the same symptoms at the same time year after year, you are likely suffering from allergies. Frequent sneezing and itchy, watery eyes are more often associated with an allergy, rather than a cold. Also, a clear nasal discharge suggests that you are suffering from allergies. When you have a cold, the mucus is usually greenish or yellowish. A low-grade fever may also indicate a cold. Sometimes it can be hard to tell the difference between seasonal allergies, a cold or another condition. That's when skin tests and an evaluation by an allergist may be necessary.