Allergy season depends on where a person lives and what he or she is allergic to. For example:

• Spring allergies: In some parts of the United States, spring allergy season can start as early as February and last through the summer. It all depends on geographic location and when grasses, trees, and weeds begin pollinating. March and April tend to be known as high spring allergy season months when most people experience the worst of their symptoms.
  
  
• Summer allergies: Spring allergy season can continue into the summer months, as grasses and weeds continue to produce pollen.
  
  
• Fall allergies: The fall season can be especially difficult for people who have allergic sensitizations to mold, as mold spores thrive in damp locations such as fallen leaves, dirt, and rotting wood.⁴ This time of year is also challenging for those with ragweed sensitization, as ragweed usually begins to pollinate in mid-August and may continue until a hard freeze.⁵
  
  
• Winter allergies: Winter allergies can occur if a person is allergic to indoor allergens, such as mold, dust mites, and animal dander, and may worsen during the months of November through January due to increased exposure to these indoor allergens.

Symptoms can change from day to day, depending on the weather. For example, high humidity can make mold grow quickly, while pollen counts can surge when it’s warm and windy. Other allergic triggers may be involved, too. Learn more about the symptom threshold.

A common cold has similar symptoms to seasonal allergies. However, a reaction to a cold is caused by a virus while a reaction to an allergen is the result of the immune system responding to a substance it has deemed a threat. Learn more about head, eyes, ears, nose, and throat symptoms. 

Five ways to tell your seasonal allergies from a cold:⁶

1. Colds can produce a fever; allergies cannot.  
2. Colds typically don’t cause itchy, watery eyes. Allergies typically do. 
3. Cold symptoms aren’t likely to last more than two weeks, but many people with seasonal allergies will experience symptoms for six weeks at a time.  
4. Sore throats can accompany colds but rarely occur with allergies. 
5. Colds can occur during any season, while seasonal allergy symptoms will likely appear at the same time each year. 

Seasonal allergies can cause tiredness and fatigue. There are two main reasons: first, when your body’s immune system responds to an allergen, it releases histamines. These histamines can interfere with your sleeping patterns, which leaves you feeling groggy the next morning, and they can lower blood pressure, which also makes you feel tired.⁷ Secondly, seasonal allergies cause stuffiness, runny nose, sneezing and other respiratory symptoms, and these also prevent us from getting a good night’s sleep.⁸ Both of these factors contribute to a feeling of tiredness when you’re actively suffering from seasonal allergy symptoms.