(NEXSTAR) – That extra head congestion you’ve been feeling lately may not all be in your head, so to speak.

new report on seasonal allergies found the growing season has lengthened by more than two weeks, on average, nationwide. A longer growing season means more days of sniffles, sneezes and headaches for allergy sufferers.

Climate Central, an organization of scientists and journalists focused on studying the impacts of climate change and warming global temperatures, analyzed temperature data from 203 U.S. cities since 1970. They found allergy season is worsening in at least eight Texas metro areas.

El Paso saw the biggest shift — the allergy season there has grown 50 days longer over the past 52 years, according to the report.

The Texas cities where allergy season has grown the most since 1970, according to Climate Central, are:

  1. El Paso: 50 days longer
  2. Dallas-Fort Worth: 21 days longer
  3. Sherman: 20 days longer
  4. Tyler: 18 days longer
  5. Odessa: 12 days longer
  6. Wichita Falls: 9 days longer
  7. Amarillo: 7 days longer
  8. Abilene: 6 days longer

Climate Central’s research found allergy season isn’t just getting longer, it’s also getting more intense.

It’s largely because warming temperatures have essentially shortened the length of deep-freeze winters and extended the length of seasons where allergen-producing plants thrive.

“Earlier spring and longer periods of freeze-free days mean that plants have more time to flower and release allergy-inducing pollen,” Climate Central wrote in its report.

Of the 203 cities analyzed nationwide, 172 (about 85%) saw freeze-free seasons grow longer — many by more than a month.

In Texas, the only cities to see allergy season grow shorter since 1970 were Waco, San Angelo and Lubbock.