April is one of the peak months for seasonal allergies across much of the United States. Tree pollen is the primary driver, and by mid-April, concentrations in the air are often high enough to cause significant symptoms for the roughly 60 million Americans with allergic rhinitis. If you’ve noticed sneezing, itchy eyes, or a stuffy nose ramping up this time of year, it’s not a coincidence.
Why April Is a Peak Month for Pollen
Spring allergy season technically begins in late February or early March in warmer parts of the country, but April is when things intensify nearly everywhere. That’s because dozens of tree species release pollen in overlapping waves throughout the month. Red maples are among the first trees to flower, often starting before April even begins. By mid-March to early April, serviceberry trees are blooming. Eastern redbuds start producing pollen as early as March and continue into April. Flowering dogwoods bloom from March through May. And black cherry trees kick in during late April, extending the pollen load into May.
These aren’t rare ornamental species. They’re common across the eastern and central U.S., lining streets, filling parks, and growing wild at the edges of woodlands. Oak, birch, and ash trees also release enormous quantities of pollen in April, and because tree pollen is designed to travel on the wind (unlike heavier flower pollen carried by insects), it can drift for miles. A single oak tree can produce millions of pollen grains in a season.
What Happens in Your Body
When pollen lands on the lining of your nose, eyes, or throat, your immune system decides whether to ignore it or treat it as a threat. In people with allergies, the body produces a specific type of antibody that latches onto the surface of immune cells called mast cells. The next time you inhale that same pollen, it locks onto those antibodies, and the mast cells respond by dumping histamine and other inflammatory chemicals into surrounding tissue. This is what causes the swelling, itching, sneezing, and mucus production you feel within minutes of exposure.
Repeated exposure throughout the season keeps this cycle going and can actually increase the amount of antibody your body produces, which is why symptoms often feel worse in the middle of April than at the start. Your immune system is essentially becoming more primed to react with each pollen-heavy day.
Allergies vs. a Spring Cold
April is also a common time for lingering colds, so it’s easy to confuse the two. The simplest way to tell the difference: itching. If your eyes, nose, or ears itch, that’s almost certainly an allergy. Colds don’t cause itchiness. A few other distinctions help:
- Fever: Allergies never cause a fever. Colds occasionally do, and the flu almost always does.
- Sneezing: Frequent, repetitive sneezing fits are typical of allergies. Colds cause sneezing too, but usually less intensely.
- Duration: A cold resolves in 7 to 10 days. If your symptoms have dragged on for weeks and seem to flare on warm, windy days, pollen is the likely culprit.
- Mucus: Allergies produce thin, clear, watery mucus. If your nasal discharge turns thick and yellow or green after several days, a cold or sinus infection is more likely.
When Pollen Levels Are Highest
Pollen concentrations follow a daily pattern that’s useful to know. Counts tend to be lowest in the early morning, around 7 a.m., then climb through the late morning. The highest average concentrations typically hit around 1 p.m., making early afternoon the worst time to be outdoors if you’re sensitive. Levels gradually drop through the late afternoon and evening.
Weather plays a major role too. Warm, dry, windy days push pollen counts much higher than cool, rainy ones. Rain actually washes pollen out of the air, so the hours after a good rainfall are often the most comfortable for allergy sufferers. However, thunderstorms can break pollen grains into smaller fragments that penetrate deeper into the lungs, sometimes triggering asthma symptoms even in people who normally only get a runny nose.
The Season Is Getting Longer
If it feels like your allergies start earlier and last longer than they used to, you’re not imagining it. Warmer temperatures are pushing plants to bloom sooner in spring and continue producing pollen later into fall. The effect is most pronounced in the northern U.S., where the growing season has extended by up to two to three additional weeks compared to previous decades. Southern regions have seen less dramatic shifts, partly because their growing season was already long.
Longer seasons mean more total pollen exposure over the course of a year, which can worsen symptoms even if the daily pollen counts haven’t changed much. For people in northern states, April allergies that once started mid-month may now begin in late March.
Reducing Your Exposure
The most effective strategy is limiting how much pollen gets into your home and onto your body. HEPA filters are remarkably good at this. According to the EPA, a true HEPA filter removes at least 99.97% of airborne particles, including pollen. Running a HEPA air purifier in your bedroom can make a significant difference in sleep quality during peak season. Keep windows closed on high-pollen days, even if the weather is pleasant.
Showering and changing clothes after spending time outdoors keeps pollen from accumulating on your skin and hair and transferring to your furniture and bedding. If you hang laundry outside to dry in April, you’re essentially turning your sheets into a pollen collection surface. Use a dryer during peak weeks instead.
Timing outdoor activities helps too. Since pollen peaks in the early afternoon, exercising or doing yard work in the early morning or evening reduces your exposure. Wearing sunglasses outdoors provides a simple barrier that keeps pollen from landing directly on your eyes.
Over-the-Counter Allergy Relief
Modern antihistamines are the first line of relief for most people with seasonal symptoms. Second-generation options like cetirizine and loratadine are taken once daily and cause far less drowsiness than older medications like diphenhydramine. They work by blocking the histamine your mast cells release, reducing sneezing, itching, and runny nose. For best results, start taking them before your symptoms peak. If you know April is your worst month, beginning in late March gives the medication time to build up its effect.
Nasal steroid sprays are particularly effective for congestion, which antihistamine pills don’t always fully address. These sprays reduce inflammation directly in the nasal passages and work best with consistent daily use rather than occasional doses. For itchy, watery eyes, antihistamine eye drops provide targeted relief.
For children, second-generation antihistamines are the preferred choice. First-generation antihistamines (the older, sedating type) should be avoided in children under six because of risks including respiratory depression. Liquid formulations are available for younger kids who can’t swallow tablets.
If over-the-counter options don’t provide enough relief, allergy testing can identify your specific triggers, and immunotherapy (allergy shots or sublingual tablets) can gradually reduce your sensitivity over time. This approach takes months to years but can provide lasting improvement that outlasts the treatment itself.