When Is Allergy Season—And When To Start Preparing?

Trying to figure out what months are allergy season can feel like something of a trick question. For those who're allergic to year-round allergens like dust mites and pet dander, every day is allergy season. But if we're talking about seasonal allergens like pollen, grass, or ragweed, allergy season starts when the trees start budding, meaning it varies depending on what part of the country you live in.

So how can you know when allergy season begins for you, and what can you do to make it as bearable as possible? Here's what you need to know.

When Is Allergy Season?

In the US specifically, spring allergies (tree pollen in particular) can start as early as February and last until early summer, according to the American College of Allergy, Asthma, and Immunology (ACAAI).

Next comes grass allergy season, Josef Shargorodsky, MD, an otolaryngologist at Coastal Ear Nose and Throat in New Jersey, told Health. "The grass season lasts all summer," Dr. Shargorodsky said. Finally, fall allergies—the main culprit of which is ragweed—begin in August and can last until the first snowfall, Dr. Shargorodsky said.

There are some exceptions to that, however: The ACAAI noted that in tropical climates grass allergies may be present for a large portion of the year, and an especially rainy spring can help plants grow more rapidly, causing summer allergies to last well into the fall.

And, like so many other things, allergy season has been affected by climate change. According to a February 2021 study published in the journal Proceedings of the National Academy of Sciences, the season had been arriving 20 days earlier than it did in 1990. Plus, it contained at least 20% more pollen.

When Can You Start Taking Your Allergy Medications?

As a general rule, allergy treatment should begin at least a couple of weeks before the start of allergy season, to help you stay ahead of the itching, sneezing, drippy nose, and wheezing. "The majority of hay fever [allergy] medications work best if started before a pollen season begins," Luz Fonacier, MD, head of allergy at NYU Langone Hospital–Long Island and president of the ACAAI, told Health.

If you use nasal antihistamines, steroids, oral antihistamines, or eye drops for seasonal allergies, Dr. Fonacier advised against waiting until your symptoms are unbearable to start treatment. And don't stop taking them too early, either. "The misery can linger until the end of the season, so wait a few weeks before stopping treatment," Dr. Fonacier said.

How To Stay Ahead of Allergy Season

First: If you've felt symptoms before but haven't been officially diagnosed with allergies, it may help to pay attention to those specific patterns. So if you've felt lousy for the last few years around March and have experienced the same symptoms—whether this is a runny nose, sneezing, congestion, or itchy or watery eyes—it's probably a good call to make an appointment with an allergist before the next allergy season starts.

"If you always think you have a cold in March but remember having three of the same symptoms last year, you may have allergies," Janna Tuck, MD, an ACAAI spokesperson and allergist in Santa Fe, New Mexico, told Health.

For regular allergy sufferers, the goal is to prevent allergic reactions before they happen. A few ways you can be prepared for the season is by keeping an eye on pollen counts (these numbers are usually announced on-air by local weather reporters) and, if you're traveling, to keep an eye on potential pollen counts in your destination town or city.

By staying on a schedule with your allergy medication, you can keep your immune system strong and ensure that you won't need more medication to keep future allergic episodes at bay.

And, while seasonal allergies—whether they come in the form of a stuffed nose, itchy eyes, or constant sneezing—aren't life-threatening, you can have severe symptoms if you also have asthma.

"Allergy symptoms can be quite severe for asthma sufferers," Dr. Tuck said. "If you have asthma and have difficulty breathing or are coughing a lot, that's another important reason to see a specialist, get tested, and get on a good treatment plan that might include regular allergy shots—the one thing that prevents asthma attacks stemming from your allergies."

What To Do if Your Usual Allergy Medications Don't Work

Many treatments are available to ease your allergy symptoms, including nasal sprays (both over-the-counter and prescription), eye drops, and antihistamines. "Oral antihistamines help the itchy, sneezy and runny nose, while intranasal antihistamines help the itchy, sneezy, runny, and congested nose," Rhonda J. Myers, MD, PhD, allergist with Providence St. Joseph Hospital in Orange County, California, told Health. Another option is intranasal corticosteroids, which help all these symptoms but must be used daily to be effective, Dr. Myers said.

If your usual meds aren't working, it's time to see your healthcare provider again. "An allergist has advanced training and experience to properly diagnose your condition with a good history, examination, skin testing, or a blood test," Dr. Fonacier said. "They can help you identify your allergy triggers, provide advice on how to avoid them, and even detect complications early.

There are several possible reasons for your meds not working, including the wrong diagnosis (i.e. you have a sinus infection and not seasonal allergies), high exposure to the allergen, or inability to avoid the exposure. You might also have started your treatment too late, Dr. Fonacier said. Whatever is at the root of it, your healthcare provider can help you get to the bottom of it—and hopefully find some relief from the sneezing.