Achoo! Oak allergy symptoms are peaking and pesky oak “worms” are everywhere

In fact, the highest oak count in San Antonio in 26 years was recently recorded

Itchy eyes, a scratchy throat, and a stuffy nose -- it’s that time of year again for those who suffer from an oak allergy.

Oak season peaks in late March and early April. It usually comes to an end in early May. (KSAT 12)

Oak trees pollinate in late March and early April, producing hanging clusters of pollen called “catkins." The pollen is then dispersed by the wind, irritating those who breathe in the pollen grains.

Catkins are clusters of pollen that develop on oak trees when they pollinate. (KSAT 12)

Not only do pollinating oak trees cause wheezing and sneezing for millions of locals, but they also create a bit of a headache for those who own lawns. The spring brings new growth to the trees, pushing off the older, brown oak leaves. The result are piles of oak leaves on front lawns, patios, sidewalks, and backyards.

Record Oak Season

The pollen count Sunday, April 11, 2021 (Copyright 2021 by KSAT - All rights reserved.)

On April 11, 2021 our allergist reported an oak count of 40,500 pollen grains per cubic meter of air. That’s the highest pollen count recorded by our allergist in 26 years! On April 2, 1995 the pollen count was recorded at 42,000 pollen grains per cubic meter of air. Oak season may be particularly bad this spring because of the lack of rain this April and a late start to oak season because of February’s deep freeze.

Seeing “Worms”?

In addition to the yellow pollen and brown oak leaves, you may notice “worms” everywhere. These are actually moth caterpillars that feed on the new, green oak leaves. Usually, after a windy day the caterpillars that hang by a thread of silk become detached, falling to the ground.

Generally, these bugs are harmless, and a great source of food for local critters. However, an extreme infestation of the caterpillars on an oak tree may require a bio-pesticide. Contact a trusted arborist if you think there may be a problem.

A look at an oak caterpillar (Copyright 2020 by KSAT - All rights reserved.)

Oak season usually comes to an end in early May.

Don’t forget that your KSAT Weather Authority Team updates the pollen count each morning - even on the weekends! Bookmark this page so that you can check it daily.


About the Authors:

Sarah Spivey is a San Antonio native who grew up watching KSAT. She has been a proud member of the KSAT Weather Authority Team since 2017. Sarah is a Clark High School and Texas A&M University graduate. She previously worked at KTEN News. When Sarah is not busy forecasting, she enjoys hanging out with her husband and cat, and playing music.

Kaiti Blake is a child weather-geek-turned-meteorologist. A member of the KSAT Weather Authority, Kaiti is a co-host of the Whatever the Weather video podcast. After graduating from Texas Tech University, Kaiti worked at WJTV 12 in Jackson, Mississippi and KTAB in Abilene.