Texas Monthly described it as a scourge.

A plague.

A widespread suffering responsible for runny noses, itchy eyes and hundreds of sneezes.

That was in 1986, and more than 30 years later, mountain cedar still torments allergy sufferers across Texas this time of year.

Heavy pollen counts, often rising after a hard freeze, flood the air, leaving behind a tsunami of yellow, snowy-like coating, according to UT Southwestern Medical Center.

But where does an allergy called "mountain cedar" — in the not-exactly-mountainous state of Texas — come from? And while many allergy sufferers might associate spring and fall as tough seasons, why does mountain cedar flare up in January?

Here's a quick explainer:

It starts with the Ashe juniper. The cone-bearing evergreen tree, often found throughout Central Texas, in particular in the Hill Country, is what produces mountain cedar. While Ashe junipers are more heavily concentrated near Austin, their pollen is dispersed further north by wind. As the Texas Monthly story noted, this causes allergy problems from the Red River to the Rio Grande.

Why January? First off, North Texas' climate often translates to year-round allergy issues. In the case of mountain cedar, Ashe junipers typically produce and release pollen between December and February, according to the Texas A&M Agrilife Extension office.

A hard freeze, especially the kind North Texas has experienced this month, can trigger the release of mountain cedar, UT Southwestern's Dr. Shelly Harvey wrote last month.

Once it's here, it can stay for a while. Last year, mountain cedar arrived in North Texas on Jan. 8 and was present for all but two days the rest of the month, according to the Star-Telegram.

The pollen count from mountain cedar on Tuesday was already in the "high" range. Mild, dry weather should keep the pollen counts high, though there is rain in the forecast for North Texas this weekend.

What are the symptoms? Common allergy reactions are the symptoms, such as sneezing, runny nose, and itchy eyes. Prevention measures include replacing air conditioning filters, closing windows and avoiding the outdoors, according to UT Southwestern.