In many parts of the U.S., ragweed allergy season starts around August,  peaks in mid-September, and can last through the first frost, which can be in October or November.

Some studies suggest that ragweed pollen is the main cause of allergies in  North America. Over 50 million people in the U.S. have allergies to ragweed pollen. (1)

If you notice your allergies are getting worse as summer ends or in early autumn, then ragweed pollen may be the reason. (2) However, you may need allergy testing to figure out what's triggering your allergies.

In this article, we’ll provide a comprehensive ragweed season guide that answers the most important questions you may have about ragweed allergies.

What Is a Ragweed Pollen Allergy?

A ragweed pollen allergy occurs when your immune system mistakenly sees ragweed pollen as a threat and releases chemicals like histamine, which can trigger common allergy symptoms such as nasal congestion and itching. (1, 3) 

Ragweed (Ambrosia artemisiifolia) is a weedy plant, and most species are native to North America.  (4) Its pollen is made of tiny, lightweight particles that float easily through the air and can travel long distances.

Ragweed often sheds most of its pollen in late summer. One ragweed plant can produce up to 1 billion pollen grains, which can cause allergic rhinitis or hay fever during this season, especially in areas where it is common across the eastern and central United States. (1)

Some people sometimes confuse ragweed with goldenrod and blame them for allergy problems because both plants bloom at the same time and grow in similar areas.

Here are some ways to tell them apart:

When is Ragweed Season?

Ragweed season typically starts in late summer (August) and continues through November. Depending on the region, peak ragweed season is often mid-September.

Ragweed season typically lasts 6 to 10 weeks, but exactly when it starts and ends depends on where you live, the weather, and when the first frost arrives. (1)

Here is what to expect: (1)

When Does Ragweed Season Start and End Where You Live?

Areas with warmer temperatures and lower humidity may have higher ragweed pollen counts and earlier, longer ragweed seasons, as these conditions create the ideal environment for ragweed pollen release. (5)

Here are some potential ragweed pollen start and end dates depending on where you live:  (6,7)

Want to learn more about other pollen allergies? Read our Pollen Season Guide: Everything You Need to Know to Survive Pollen Season.

Symptoms of Ragweed Pollen Allergy

Common symptoms of ragweed pollen allergies include:

• Nasal congestion

• Sneezing

• Watery, itchy or irritated eyes

• Postnasal drip

• Runny nose

• Coughing

• Scratchy throat

• Eye swelling

• Weakness or fatigue

• Ragweed rash

Ragweed Allergy or a Cold?

Ragweed season overlaps with the start of cold season, so it's easy to confuse ragweed allergy symptoms with a cold. Here’s how they differ:

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What Makes Ragweed Allergy Season Feel Worse?

Common factors that make ragweed pollen season feel worse include:

• Location: areas with warmer temperatures and carbon dioxide concentrations could experience longer allergy seasons and higher pollen counts. (8)

• Delayed first fall frosts: Ragweed pollen allergy season often ends at the first hard frost. (9, 10) If this is delayed, the ragweed pollen season may be longer, and ragweed allergy season can feel worse.

• Time of day: Ragweed pollen levels often peak from morning to midday, so if you are outdoors during this time, allergy symptoms may feel worse. (11, 12)

• Warm, windy weather: Warm, windy days can cause pollen counts to surge as ragweed pollen is easily carried by wind. (13)  The higher the pollen counts, and the longer it is in the air, the worse allergy symptoms can be felt. (14)

How Can You Prepare for Ragweed Season?

Ragweed allergies can make an otherwise beautiful fall season feel miserable. To help reduce symptoms, here are some of the best ways to get ahead of ragweed season: (1, 5, 14)

Before peak season

• Check your local forecast to know when ragweed season starts in your area.

• Have a jump start on your allergy medications, such as over-the-counter or nasal sprays, one or two weeks before ragweed allergy starts where you live.

• Consider starting long-term treatment such as allergy immunotherapy (allergy drops or allergy shots) in spring or early summer.

• Prepare your home for pollen season by checking air-conditioning filters and getting a NIOSH N95 mask for outdoors.

During peak pollen

• Shower and change clothes after going outdoors

• Avoid drying clothes outdoors.

• Keep windows closed on warm, windy days.

• Stay consistent with your treatment plan.

• When outdoors, wear sunglasses and a hat outside to keep ragweed pollen out of eyes and hair.

• Consider staying indoors with windows closed when ragweed pollen counts are high.

Treatment for Ragweed Allergy Season

There is currently no cure for ragweed allergy; however, some medications can help you manage symptoms:

1. Over-the-counter and prescription allergy season:

Your healthcare provider may prescribe some allergy medications such as antihistamines  (fexofenadine, cetirizine), nasal corticosteroids (fluticasone, budesonide), and nasal decongestants (Oxymetazoline, Xylometazoline).

Allergy medicines provide only temporary relief from ragweed allergies and must be taken at least two weeks before pollen season starts. (15)

2. Ragweed Allergy Immunotherapy:

Unlike conventional allergy medicines, ragweed allergen immunotherapy (allergy shots or drops) changes how your immune system reacts to ragweed pollen and may, over time, reduce your allergies rather than mask symptoms. (16)

Allergy immunotherapy is recommended for patients with ragweed allergy who don't get enough relief from regular allergy medications or who are constantly exposed to ragweed pollen. (17)

Get Ahead of Ragweed Season with Quello Allergy Drops

Ragweed season doesn’t have to mean weeks of sneezing, congestion, and missing out on the parts of fall you enjoy.

Our goal at Quello is to help you find lasting allergy relief so you can enjoy every activity you want (indoors or outdoors) without constant symptoms getting in the way.

With Quello, you can start by identifying your allergy triggers. If testing shows that ragweed is one of them, you’ll meet with a licensed provider who can review your results, symptoms, and health history to determine whether allergy drops may be a good fit for you.

If prescribed, your personalized allergy drops are formulated based on your allergy profile and designed to reduce your sensitivity to the ragweed allergens that trigger your symptoms.

Ready to find out what’s triggering your fall allergies? Start Your Free Allergy Test

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Still have questions? Visit our FAQs to learn more about allergy testing, treatment, and what to expect.

FAQs

How long does ragweed season last?

Ragweed pollen season can last between 6 and 10 weeks, depending on where you live. In warmer regions, ragweed season can last longer because the first hard frost may occur later.

When does ragweed season peak and end?

In most parts of the United States,  ragweed pollen season often starts around August and can last through the first frost, which can be in October or November.

When is ragweed pollen highest?

Ragweed pollen levels are highest in the morning up to midday during ragweed pollen season. However, weather conditions and local pollen patterns can affect the exact timing.

Does rain make ragweed allergies better or worse?

Rain can make ragweed allergies better or worse depending on the extent of rainfall.   Heavy downpours can make ragweed allergies worse, as they break pollen into smaller pieces and scatter it through the air.  

Light, steady rain showers, on the other hand, can wash the pollen away, keeping it from flying through the air and temporarily reducing exposure.

Can ragweed allergies cause a fever?

Ragweed allergies do not typically cause a fever. If you feel feverish, it may suggest a cold or flu rather than seasonal allergies.