Iowa allergy sufferers waiting for relief

A good rain could help, but allergy sufferers might not find longer-term relief until Iowa has a hard freeze.

The allergy season has been extended this year in areas of the state where temperatures have not dropped below freezing.

Iowa's first average frost ranges from late September in the north to early to mid-October in areas to the south.

Ragweed and other pollens typically disappear with a light frost, but it takes a hard freeze to diminish the outdoor mold that is even more of an allergen for many people, said Dr. Amy Dowden, an allergy and immunology physician at University of Iowa Hospitals and Clinics in Iowa City.

“Mold is ubiquitous,” Dowden said, noting that outdoor mold can become indoor mold when windows are left open.

The outdoor mold, alternaria, is a primary allergy trigger in Iowa, she said.

Dowden noted that the symptoms for mold allergies are similar to hay fever, with watery, itchy eyes and runny noses.

Josh Baynes, KCRG-TV9 meteorologist, said parts of Eastern Iowa have experienced frost, but temperatures have not stayed below 32 degrees for an extended period of time to cause a hard freeze.

Rain forecast for this weekend follows a particularly long dry spell in Eastern Iowa. The last widespread rain was Sept. 25, Baynes said.