What To Do When Seasonal Allergies Affect You All Year

Seasonal allergy symptoms often start in March and start to wane by November, leaving many in a near-all-year ordeal of sniffling and sneezing. Get relief from your symptoms.

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Updated August 10, 2026

By Amit Bhalodia, DO, Family Medicine, Virtua Primary Care

Seasonal allergy symptoms often start in late March and start to wane by the end of November. Given the long time span, it can feel like seasonal allergies are an all-year ordeal of sniffling and sneezing.

What is a seasonal allergy?

Seasonal allergies are similar to other allergies and develop when the body’s immune system overreacts to something in the environment. It can be triggered by a variety of plants, and its severity can be affected by the current pollen count.

How long do seasonal allergies last?

While most seasonal allergies start in the spring and last through late fall, the weather where you live can affect the length of time that you experience symptoms. Some studies suggest that rising temperatures and higher carbon dioxide levels contribute to longer growth time of allergen-producing plants.

What causes seasonal allergies?

In the spring, grass and trees are common allergy triggers
In the fall, about 75 percent of people allergic to spring triggers also have reactions to ragweed. Ragweed blooms and releases pollen from August to November, but levels are often the highest in early to mid-September
Mold is a common trigger, especially where it thrives, in warm, moist environments
Smoke from a fire pit or fireplace
Real Christmas trees, wreaths, and swags
Dusty holiday decorations coming out of the attic, garage, or basement

What does the pollen count mean?

The pollen count is calculated from a 24-hour air sample. This calculation is a representative sample for the entire day. Pollen count can be broken up into simple categories ranging from low to very high.

When the pollen count is low, people with common seasonal allergies are less likely to experience symptoms. When the pollen count is very high, it can lead to individuals sensitive to allergies having trouble sleeping and difficulty breathing.

How can I prevent seasonal allergies?

Keep your windows closed at home and in your car during allergy season.
Monitor pollen and mold levels in your area
Avoid exercise outdoors when levels are high.
Wear a facemask when cutting grass, raking leaves, or doing other outdoor chores.
Change your clothes, take a shower, and wash your face and hair when you come in from working or exercising outdoors.

Seasonal allergy symptoms

It can be easy to confuse allergy symptoms with those you experience with a common cold or virus. However, if you have seasonal allergies, your congestion likely is accompanied by the following:

An itchy nose or throat
Itchy eyes
Post-nasal drip
Some even experience itchy skin or redness with seasonal allergies.

What happens if I leave my allergy symptoms untreated?

Left untreated, the inflammation that occurs from exposure to allergens can cause mucus to build up in the sinuses, creating a warm, moist environment that’s perfect for viruses and bacteria to thrive. That’s often how your allergy symptoms turn into a case of sinusitis—complete with more severe congestion symptoms, including thick, discolored mucous, sinus pressure/pain and, possibly, fever.

What is the best allergy medicine to relive symptoms?

If you experience seasonal allergies every year, talk to your primary care provider about what over-the-counter allergy medicine may work best for you.

Oral medications like loratadine (Claritin), fexofenadine (Allegra), or cetrazine (Zyrtec) offer fast relief for allergy symptoms.
A steroid nasal spray such as fluticasone (Flonase) or mometasone (Nasonex), when instilled correctly, can help reduce post-nasal drip and sinus congestion and possibly help prevent your symptoms from worsening into a sinus infection.
Other prescriptions medicines can help people who experience chest tightness or difficulty breathing with seasonal allergies.

When is the best time to use allergen relief medication?

It’s best to start using these medicines a few weeks before seasonal allergies kick in and continue using them through the fall. You can monitor pollen and mold levels in your area through most weather apps, and ease off these medicines when the levels drop—usually around first frost, typically when temperatures reach 32 degrees Fahrenheit. Some people need to use them year-round.

What should I do if my allergy symptoms worsen?

Drink lots of water to stay hydrated.
Use an over-the-counter medication like Mucinex to relieve severe congestion.
If you’re using a nasal steroid spray, hold your chin to your chest, put the bottle in your right hand and the bottle tip in your left nostril to spray; repeat using your left hand to spray into your right nostril. This method helps get the spray deeper into your sinuses where it works best and helps prevent nasal bleeding.
Heat a bowl of water in the microwave until it’s steaming. Put a towel over your head and lean over the bowl of water, inhaling the steam for five to 10 minutes. Repeat a few times a day.
Use a saline nasal spray to hydrate your nasal passages and to help loosen mucous so you can get rid of it by blowing your nose.
Run a humidifier at night to help you breathe and to prevent your nasal passages from drying out.

If you follow this at-home treatment regimen for seven to 10 days without improvement, call your primary care provider for evaluation.