ST. PETERSBURG, Fla. (AP) — Pollen: It’s on your car, in the air and especially in your sinuses.

From Florida to Texas to Colorado, 2010 is shaping up to be a monster of an allergy season. The words ‘‘pollen’’ and ‘‘allergy’’ are among the top 10 trending topics on Twitter in several U.S. cities. Everywhere, it seems, is covered in a fine yellow dust that irritates our lives. Experts say it’s the worst they’ve seen in years in many areas.

‘‘It’s wicked bad this year,’’ said Dr. Mona Mangat, an allergy specialist in St. Petersburg, Fla., who can’t recall a worse year in the six she’s worked there. ‘‘We’re just overwhelmed with patients right now. We’re double- and triple-booked with new patients, trying to work people in because we know how much people are suffering.’’

This year is especially bad in the Southeast, weather experts say, likely due to winter’s unseasonably cold weather.

‘‘That may have helped delay some of the plants from blooming as early as they may have wanted to,’’ said John Feerick, senior meteorologist at AccuWeather. ‘‘It’s the fact that everything is coming out all at once.’’

High winds in some areas also spread the misery.

‘‘We had a perfect storm this year,’’ said Dr. William Storms, professor at University of Colorado and a clinician. ‘‘It’s the worst I’ve seen in 10 years.’’

It’s enough to bring some to tears. Take 5-year-old Sam Wilson of St. Petersburg. His mom gives him Claritin in the morning, Nasonex and Benadryl at night, and he receives four allergy shots every week. The sidewalks of his hometown are covered in what look like piles of dried, brown worms — but they are mounds of oak tree pollen.

His mother said that when the pollen is at its worst, the boy’s eyes water and itch, he can’t breathe through his nose and his throat burns.

‘‘His reaction yesterday was pretty bad,’’ said his mother, 34-year-old Joanna Wilson on Thursday. ‘‘He couldn’t breathe, he was completely congested, and crying.’’

Oak trees are the culprit in many places in the Southeast.

The trees produce 3,000 to 6,000 pollen particles per cubic meter; it only takes 10 particles to trigger an allergic reaction.

Angel Waldron, a spokeswoman for the Washington, D.C.-based Asthma and Allergy Foundation of America, said that allergy seasons have been getting longer over the years, with six to eight weeks of suffering expected this year in some areas.

‘‘When your car is green when you wake up in the morning, it’s shocking,’’ she said.

Waldron’s group compiles a list each year of most challenging places to live for allergy and asthma sufferers. Topping the list: Knoxville, Tn., followed by Louisville, KY, Chattanooga, TN, Dayton, OH and Charlotte, NC.

‘‘We rank them based on pollen counts, number of medicines used, both prescription and over the counter, and number of specialists in the area,’’ she said.

J.P. Levins, executive Web producer for the site pollen.com, said he’s received a lot of e-mails from suffering Floridians — but he expects more complaints from other parts of the U.S. soon.

‘‘The season is actually just picking up,’’ he said, adding that most of the country is facing high pollen counts.

Tree pollen season should subside within a few weeks, but experts say some will continue to suffer because grass and weed allergies rise in the summer months.