We all know about pollen in the spring, that season of yellow clouds of anguish for allergy sufferers.

But as fall approaches and the summer haze fades, you still may find yourself with itchy eyes, a scratchy throat or a runny nose. If so, you could be one of 36 million Americans who suffer from seasonal allergies.

Most associate hay fever and pollen allergies with spring, when the sticky yellow dust from trees and flowers covers cars, patios and roadways as if someone spilled a giant packet of lemon Kool-Aid.

But allergy sufferers may find fall pollens to be just as rough on their tender sinuses. And the recent cooler weather seems to have triggered the new pollen season.

"The cool weather the last week or 10 days has brought on heavier pollen production than we've seen, so it's that time of year," said Billy Skaggs, county extension coordinator for the UGA Cooperative Extension in Hall County.

Depending on the weather, the pollen may be with us for awhile, at least until the first frost or heavy rainfall.

"Usually, the season can last quite a while with different species producing pollen at different times," Skaggs said. "It can go three to four weeks, without a doubt."

The recent dry, warm spell could be making pollen even worse, state climatologist David Stooksbury says.

"A dry, warm fall can aggravate it because the pollen is not washed out of the air," Stooksbury said. "And if it's warm, there is no killing freeze and that will allow those plants to keep blooming longer."

Skaggs says the biggest pollen producer is the aptly named ragweed, a common plant that grows wild along roadsides, in pastures and in hayfields.

Other pollinators this time of year include grasses such as Bermuda, fescue and Johnson grass, bluegrass later in the season, and tree pollen such as oak and elm, Skaggs says.

And while the air may look clear, it is the pollen we don't see that bothers us most.

"Most of the plants that produce the most allergens are not the real showy, heavy flowering plants," Skaggs said. "Most of those are pollinated by bees and insects, and the pollen is larger. It's the microscopic pollen that causes the most allergies."

To keep these nuisances out of your own yard, Skaggs recommends mowing grass before it goes to seed and cleaning out underbrush where weeds can thrive.

But even then, there's plenty of pollen carried by the wind to keep us sneezing.

That makes it a busy time for allergists such as Dr. Andy Nish of the Allergy and Asthma Care Center, 2150 Limestone Parkway.

"Spring and fall are kind of similar," Nish said. "The trees reach high concentrations in spring, and weeds in the fall. It is estimated that one ragweed plant can produce 1 billion grains of pollen."

When patients come to his clinic with symptoms, Nish and his staff recommend three approaches to treating them.

"Once we know what someone is allergic to, we recommend as a first step avoidance measures," he said. "That might include staying indoors during time of day when pollen levels are highest, which is typically morning to early afternoon. Keeping doors and windows closed at home and in the car ... You might consider things like taking a shower to wash it off, changing clothes, and don't dry clothes outdoors."

Step two is using medications such as over-the-counter antihistamines that can help ease symptoms, though many include undesirable side effects, particularly drowsiness. Nish recommends his patients take those only at night.

Prescription steroid nasal sprays are effective, he says, and can be taken along with antihistamines to ease suffering.

For those who need even more relief, the third step is allergy shots.

"Those are for people who have significant symptoms and who are allergic to many things, and people who don't do well with the first couple of steps," Nish said.

"I always say I'm amazed at what people will put up with, missing school and work, and thinking nothing effective is out there. There are very good treatments available for allergies so there's no point in suffering."