Allergies that are worse in damp weather. Mold may be the cause of allergies that get worse in damp weather. Mold produces spores that move, like pollen, in outdoor air during warmer months. During winter months, indoor molds can also be a problem.
Indoor allergies. Newer, energy-saving homes that are built with double- or triple-paned windows and more insulation keep heat and allergens indoors.