And for people with this pollen allergy, that means miserable symptoms such as sneezing, a runny or stuffy nose, trouble sleeping, asthma attacks, and itchy skin, eyes, nose or throat. The season usually kicks into high gear in mid-August, says Martha White, director of research at the Institute for Asthma and Allergy, a private practice in Maryland with offices in Wheaton and Chevy Chase.

Most regions in the United States experience ragweed growth between mid-August and the first frost. Each ragweed plant makes about a billion pollen grains per season – and with the help of the wind, those grains can travel up to 400 miles, according to the American Academy of Allergy, Asthma and Immunology. Also, some people with ragweed allergy experience itching and swelling around the mouth as a result of eating some common fresh fruits and vegetables. The condition is called oral allergy syndrome, and it's commonly prompted by eating bananas, cucumbers, melons and zucchini.

Some experts believe that climate changes associated with global warming may be lengthening the annual ragweed allergy season. That's bad news for the 10 to 20 percent of Americans allergic to these weeds, which studies suggest will flourish for longer each year, thanks to rising temperatures and carbon dioxide levels. One study found that between 1990 and 2007, the duration of ragweed season in the New York metropolitan area increased from 90 to 105 days. "The longer you're exposed to it, the more miserable you will be," says study co-author Leonard Bielory. "It's more misery, and it ... will lead to lost work days and lost school days."

Experts suggest getting a jump-start on symptoms before you start to feel lousy. This should come as no surprise to people accustomed to dealing with seasonal allergy symptoms, but we offer eight refreshers for making this ragweed season as painless as possible.

If your doctor has prescribed a nasal steroid in the past, make sure you have a supply at home, and start taking it immediately, White says. Popular nasal steroids include Flonase or Nasonex. The same goes for oral antihistamines, which include over-the-counter options such as Claritin (loratadine) or Zyrtec (cetirizine) as well as prescription options such as Allegra (fexofenadine) or Xyzal (levocetirizine). Also, because so many people complain of itchy eyes during ragweed season, it may be a good idea to ask your doctor for a prescription for allergy eye drops, such as Patanol (olopatadine), Optivar (azelastine) or Pataday (olopatadine), or to try an over-the-counter antihistamine eye drop like Zaditor (ketotifen fumarate).

It may feel good to catch a breeze from outside, but the pollen you're allowing to enter your home or car can make your allergy symptoms worse, White says. That's especially "if you're in a moving car, with the pollen hitting you kind of fast." Instead, use your air conditioner at home and in your car because that will filter, cool and dry the air, says Bielory, who is an allergist in a private practice in Springfield, New Jersey.

"It's not a good idea to wait until you're miserable and then compete with everybody else for an appointment," White says.

Even if you're not allergic to your dog or cat, it's probably a good idea to bathe the animal more frequently during ragweed season because it can track pollen into the house, White says.

That way, you're not introducing pollen from outside into your bed at night, experts suggest. That includes washing pollen from your face and hair, so it doesn't wind up on your pillow, Bielory says.

This type of treatment can be effective for up to 90 percent of patients who are allergic to ragweed, according to the AAAAI. A 2003 update of a Cochrane Collaboration review found that allergy immunotherapy helps to ease asthma symptoms, reduce the need for medicines and decrease the risk of severe asthma attacks during future exposure to allergens. Allergy immunotherapy is typically covered by health insurance.

...and avoid being outdoors on days when counts are high. AAAAI offers an online tool that provides pollen counts in various locations across the country.