Columbia, the capital of and largest city in South Carolina, has been moving up in the rankings – from No. 34 in 2013 to No. 13 now. Both pollen score and medicine use are contributing. The city gets an average rainfall of 47.98 inches, about 9 more than the national average (7 Workout Solutions for Rainy Days). “The rain provides future grass, weed or tree pollen growth,” Dr. Borczuk says. “Springtime in the past meant a slower pattern of pollen released from different species of trees. It now appears that within a few days the pollen from all or most of the trees is aerosolized at the same time, heightening allergies.”