There has been one positive from the Arctic chill that gripped North Texas this week.

The deep freeze held off the annual invasion of mountain cedar, the winter pollen that blows in and makes many allergy sufferers miserable, with steady sneezing, itchy eyes and scratchy throats.

While pollen counts have been mostly nonexistent during the recent freeze, once things warm up it probably won’t take long for mountain cedar sufferers to start sneezing again.

“This hard freeze will make the pollen release,” said Dr. Shelly Harvey, an allergist who practices at the UT Southwestern Monty and Tex Moncrief Medical Center in Fort Worth.

Through Friday, mountain cedar had yet to make a return to North Texas, according to pollen counts. But there were moderate counts in Georgetown and heavy counts in San Antonio, where juniper trees — the producer of mountain cedar — are plentiful.

Locally, mountain cedar counts can soar on warm, windy days — often ahead of a cold front — when pollen blows in from Central Texas and the Hill Country.

During last year’s winter pollen season, mountain cedar showed up on Jan. 8 and was present for all but two days the rest of the month.

With temperatures expected to climb into the low-60s this weekend, North Texas could see a blast or two of mountain cedar. But there’s also a chance of rain, which could wash the pollen out of the air.

University of Tulsa biology professor Estelle Levetin studied the transport of mountain cedar pollen for 17 years, including once tracking it all the way from Texas to Canada.

She previously told the Star-Telegram that it needs to be 50 degrees or higher for the juniper trees to start pollinating, Other issues, such as humidity and sunlight, can also play a role in whether a tree pollinates.

On Christmas Eve, there was a moderate concentration of pollen in North Texas but counts plummeted when the cold temperatures arrived.

In Central Texas, San Antonio had a count of 27,030 — which is considered very heavy — on New Year’s Eve.

“If people know they’re allergic to mountain cedar, it would be a good idea to start a nasal steroid spray, then add an antihistamine as symptoms develop,” Harvey said.

But if the symptoms persist, Harvey said allergy sufferers may need to see an allergist and get tested, which could ultimately lead to allergy shots.

How long will the polllen stick around? Typically, mountain cedar sticks around through February.

Last year, it was showing up until March 1, just in time for spring tree pollens to start a whole new round of sneezing.

The number of high pollen days depends heavily on the weather. If it turns out to be warm like last winter, look for a number of high pollen count days. If we have more cold days like the first few days of January, it probably won’t be as bad.

Coping with mountain cedar

For those with severe mountain cedar allergies, these steps have been recommended by some allergists:

▪ Keep windows closed at home during the pollen season, especially on windy days.

▪ Keep the home dusted — but the person who is allergic should not do the dusting.

▪ Always shower immediately after working outside or spending time outside. This will help get the pollen off your skin and out of your hair.

▪ Wear close-fitting or “wraparound” sunglasses to reduce pollen in the eyes. Use artificial-tears eye drops to wash away the pollen.

▪ If you have allergies, take prescribed antihistamines and nasal sprays daily during the allergy season. They work much better to prevent allergy symptoms before they start than after.

This article includes information from Star-Telegram archives.

Bill Hanna: 817-390-7698, @fwhanna