Outdoor or Seasonal Allergies

Allergens are in the air all the time, but many trees, grasses and weeds have a certain time of year during which they pollinate. Seasonal allergies usually cause symptoms of nasal congestion, runny nose, sneezing, itchy/watery eyes and wheezing.

Missouri is known for its pollen producing trees, grasses and weeds, as well as for the seasonal allergies they cause. Trees and grasses mainly contribute to what is known as the “spring and summer allergy season” while the weeds tend to be the cause of the “fall allergy season.”


  • Cottonwood
  • Elm
  • Maple
  • Maple Leaf Sycamore
  • Mountain Cedar
  • Oak
  • Pecan/Hickory
  • Walnut
  • White Ash


  • Timothy
  • Bermuda


  • Ragweed
  • Marsh Elder
  • Pigweed
  • Thistle

If you suspect allergies, the first step is to accurately diagnose the problem with an allergy test. The St. Louis Sinus Center offers allergy testing to help patients make decisions about what allergens to avoid, as well as to determine if immunotherapy (allergy shots) may be of benefit.

St. Louis Pollen Counts

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