Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. While peak activity is typically concentrated in the colder winter months, the flu does not vanish with the arrival of warmer weather. The answer to whether you can get the flu in the spring is definitively yes, as the virus can circulate year-round. Although the highest rates of infection usually occur between fall and early spring, flu activity often extends beyond those boundaries.
The Flu Season Cycle and Late Surges
The designation of “flu season” is based on surveillance data collected by public health agencies that track the presence and spread of the virus. In temperate regions, influenza activity most frequently peaks between December and February, but the overall season can last much longer, sometimes extending as late as May. The concentration of cases in winter is partly due to environmental factors, as the influenza virus survives longer in cold, dry air.
As spring begins, the risk does not immediately disappear; rather, it often shifts. Late-season surges can occur for several reasons, including the lingering presence of strains that circulated throughout the winter. Fluctuations in spring temperatures and humidity levels can also create conditions that still favor viral transmission.
Changes in human behavior during the spring months contribute to the continued spread. Increased travel for spring break, larger outdoor gatherings, and other seasonal events bring people from different regions into close contact. This heightened mobility creates new opportunities for the virus to jump from person to person, causing a late-season spike in illnesses. The end of the flu season is defined not by a fixed date, but by a consistent drop in the number of reported cases.
How to Tell the Difference Between Flu and Spring Allergies
As pollen counts rise in the spring, many people confuse influenza symptoms with those of seasonal allergies, which can delay diagnosis and treatment. A key difference is the speed of onset. Flu symptoms appear suddenly, often escalating rapidly to cause significant illness. In contrast, allergy symptoms typically develop gradually and can persist while the allergen is present.
High fever and profound body aches are strong indicators of the flu, which allergies do not typically cause. Influenza frequently presents with a fever lasting several days, accompanied by intense muscle soreness and overwhelming fatigue. While allergies might cause mild fatigue due to poor sleep, they do not result in the debilitating body aches characteristic of a viral infection.
Specific respiratory symptoms also vary between the two conditions. Spring allergies are defined by the immune system’s reaction to harmless triggers like pollen, which often results in intense itchiness of the eyes, nose, and throat. Nasal discharge from allergies is usually clear and watery, and sneezing can be repetitive and frequent. Conversely, the flu rarely causes itchiness, and its associated cough is often deep in the chest, sometimes accompanied by mucus that is thicker or discolored.
Remaining Vigilant: Protection Measures
Even when flu activity is winding down, maintaining preventive measures remains important for avoiding late-season infection. Good hand hygiene is an effective defense against respiratory viruses. Regularly washing hands with soap and water for at least 20 seconds, or using an alcohol-based sanitizer, helps reduce transmission risk.
It is also important to avoid touching the eyes, nose, and mouth, as these are common entry points for the virus into the body. If you develop symptoms, staying home from work or school is necessary to prevent spreading the illness to others in the community. Covering coughs and sneezes with a tissue or the elbow further limits the aerosol spread of viral particles.
If flu symptoms appear, seeking prompt medical attention is advisable, especially for those in high-risk groups. Antiviral medications are available that can lessen the severity and duration of the illness, but they are most effective when started very early in the course of the infection. Since the flu season can stretch into the spring, vaccination may still be recommended if the virus is actively circulating in the area.