As spring approaches, people with allergies can blame global warming for some of their suffering, according to the American College of Allergy, Asthma and Immunology. Weather conditions have a significant effect on the levels of pollen and mold in the air, which affects the severity of allergies.
That suggests mold allergens could be particularly prominent this spring given the extent of drought across the United States — dry and hot weather lifts molds from the soil to be carried by the air. In addition to tree pollen, springtime mold contributes to hay fever.