What to Know About Pollen Count

Medically Reviewed by Dany Paul Baby, MD on April 11, 2022
5 min read

Pollen count is a measurement of the amount of pollen in the air. This pollen can trigger seasonal allergies, which is also known as hay fever or allergic rhinitis.

Pollen is a powdery substance that’s created by some trees and plants as part of their reproduction process.

Three main types of pollen are counted in the pollen count.

1. Ragweed pollen. This is pollen from weeds and ragweeds, such as:

  • pigweed
  • sheep sorrel
  • sagebrush
  • lamb's quarters

Ragweed pollen season starts in August and runs through November. Pollen levels usually peak in mid-September in many parts of the United States.

2. Grass pollen. There are more than 1,000 species of grass. Only a few cause seasonal allergies, though. These include:

  • Sweet vernal grass
  • Johnson grass
  • Orchard grass
  • Bermuda grass
  • Timothy grass
  • Kentucky bluegrass

Grass pollen is seasonal and regional. The best way you can avoid grass pollen is to avoid mowing the grass or to wear a mask when mowing. You can also grow ground cover that has less pollen, such as Irish moss or dichondra.

3. Tree pollen. If you have tree pollen allergies, stay away from:

  • Oak
  • Elm
  • Walnut
  • Catalpa
  • Pecan
  • Sycamore
  • Hickory

Trees that are less likely to cause allergies include: 

  • Pear
  • Fir
  • Plum 
  • Dogwood
  • Fig
  • Redwood

Tree pollen can travel great distances, though, so even if you're not near certain trees, you may still feel the effects of tree pollen. 

In the southern US, trees release pollen as early as January. In the northern parts of the country, tree pollen season may only start in May or June. 

Plants’ production of pollen is influenced by the weather. Warmer days and milder winters mean an earlier pollen season. Cold weather often results in a delayed pollen season.

Scientists say that the warming climate has increased the length of the pollen season in the northern US. Between 1995 and 2009, the pollen season increased by up to 13 to 27 days.

In the United States, pollen sampling is carried out by various agencies and allergy clinics. A volunteer organization called the National Allergy Bureau collects data from 84 of these sampling stations.

An instrument that measures pollen count is usually located on a rooftop. This instrument collects spores for a 24-hour period. Then, it’s taken to a lab where the collected spores are examined. This will allow scientists to know the type of pollen types and concentration in the area.

A pollen forecast is a prediction of the pollen count. This is usually based on general weather forecasts and pollen data from previous years.

The pollen count depends on what type of pollen is being measured. These numbers are measured in grains of pollen per cubic meter of air.

Tree pollen

Low: 1 to 14

Moderate: 15 to 89

High: 90 to 1,499

Very high: More than 1,500

Weed pollen

Low: 1 to 9

Moderate: 10 to 49

High: 50 to 499

Very high: More than 500

Grass pollen

Low: 1 to 4

Moderate: 5 to 19

High: 20 to 199

Very high: More than 200

Mold spores

Low: 1 to 6,499

Moderate: 6,500 to 12,999

High: 13,000 to 49,999

Very high: More than 50,000

A high pollen count means that most people with any sensitivity to pollen and molds will likely experience symptoms. A very high pollen count means that almost everyone who has any sensitivity to molds and pollen will have symptoms.

A low pollen count means that only those who are extremely sensitive to pollen and mold will have symptoms.

An allergy is your body's way of reacting to something it considers an invader. Your immune system fights the allergen by releasing chemicals called histamines. These can cause symptoms like itchy, watery eyes, congestion, and sneezing.

Your doctor may recommend some medication to help relieve your pollen allergy symptoms.

Over-the-counter medications. Some over-the-counter medications may help with your pollen count allergies, including:

  • Decongestants. These can help relieve stuffiness in your nose. You can find them in an oral form like pseudoephedrine or as nasal sprays like oxymetazoline. Don’t use nasal decongestants for more than a few days in a row, though, as this may make your symptoms worse.
  • Oral antihistamines like cetirizine and loratadine. These can help relieve your watery eyes, runny nose, and sneezing. 
  • Nasal spray. This is most effective if you start using it before you have symptoms. 
  • Combination medications. Some allergy drugs combine a decongestant and antihistamine.

Nasal rinse. You can use a neti pot or squeeze bottle filled with a saline solution to rinse your nasal passages. This helps flush out allergens and mucus from your nose. Rinse the irrigation device after each use. Let it air dry.

Allergy shots. For some people, another option is allergy shots or allergen immunotherapy. This involves gradually increasing doses of the allergen. This can be in the form of injections or tablets under the tongue. Your body gradually develops a tolerance or immunity to the allergen.

Allergy tablets are intended to be a preventative measure. You should start this immunotherapy three to four months before the start of allergy season.

These are some ways to help you cope during times when the pollen count is high:

  • There’s more pollen in the morning and at night. Try to go outside when the pollen count is lower.
  • Don’t go out when it’s windy. The pollen count is usually higher when it’s windy and warm. 
  • Shower before bed. Pollen can stick to your hair, clothes, and skin. Before you go to bed at night, take a shower to wash off the pollen so that it doesn’t get on your bed. Also, remove and wash any clothing that may have pollen on it. 
  • Take allergy medicine before you go outside. This will help get the medication into your system before any allergy symptoms start.

Another way to reduce your allergy symptoms is to keep the indoor air clean. Try to:

  • Close your door and windows. This will help keep the amount of pollen in your home low. You may also want to use a HEPA filter vacuum cleaner and air purifiers.
  • Keep your house clean. Dust can contain irritants and pollen. Cigarette and fireplace smoke can also make allergy symptoms worse. 
  • Use a clothes dryer instead of hanging your clothes outside. Hanging clothes outside means that pollen collects on them.