Unseasonably warm weather early this year triggered many plants to bloom, much to the chagrin of seasonal allergy sufferers.

Even in cooler weather states, plants start to release pollens in February or March. The rollercoaster temperatures seen in many parts of the country may have triggered allergic reactions in people who have not traditionally suffered during allergy season.

In Denver, for example, high temperatures hit the mid-70s in February and then dropped to the 30s—along with some snow—in mid-March.

“Typically allergy season in the Denver area occurs between January and May, with pollen counts usually highest in this time frame. With recent warming in the area expect allergy symptoms to become more prevalent,” said Dr. Nils Foley, Medical Director with ZipClinic Urgent Care Centers in Denver, Aurora, and Westminster.

Weather is a common allergy trigger. Here are a few explanations for your symptoms based on the weather conditions, according to WebMD.com:

Dry, windy days. Wind blows pollen into the air, causing hay fever. If you have pollen allergies, shut the windows and stay indoors on windy days.

Rainy or humid days. Moisture makes mold grow, both indoors and out. Dust mites also thrive in humid air. But if you’re allergic to pollen, humid or damp days are good. The moisture weighs down the pollen, keeping it on the ground.

Cold air. Many people with allergic asthma find that cold air is a problem, especially when they exercise outside. It can trigger a coughing fit.

Heat. Air pollution is worst on hot summer days. Ozone and smog can be a serious trigger for people with allergic asthma.

Dr. Foley said the symptoms of seasonal allergies include: sneezing, itching, runny nose, watery eyes, and wheezing.

“In general the seasonal allergies to grasses, trees and weeds tend to cause nasal and sinus issues, and often make asthma symptoms worse,” he said. “Over-the-counter remedies such as saline nasal rinses and antihistamines may improve symptoms, but more bothersome issues may warrant a quick trip to your doctor or an urgent care center for an evaluation and possible prescription medication.”