The season is again transitioning, from spring to summers and some areas are also seeing early monsoons. This is also the allergy season in the US, and thanks to global warming, it has begun earlier. This has caused 25% of adults and 20% of children to experience seasonal allergies. While almost everywhere in America seasonal allergies are going on, there are certain regions where cases are more. You may be more prone to catching diseases. A recent 2025 report by the Asthma and Allergy Foundation of America ranked the 100 most populous metropolitan areas in the contiguous United States based on tree, grass, and weed pollen counts. The data also accounts for number of allergy specialists and estimates of over-the-counter sinus and allergy medication usage. Each city was scored based on the three factors, and the scores would top out of 100.00 for the worst city for allergies to 45.29 for the best. Each metropolitan area was also rated as “worse than average,” “average,” or “better than average” based on its levels of tree, grass, and weed pollen. Similar ratings were given for medication usage and access to allergy specialists.10 Worst US Cities To Live In During Seasonal Allergies10. At number 10 is Greensboro, North Carolina with a score of 82.08. The pollen rating for this region is worse than average. 9. At number 9 is Greenville, South Carolina with a score of 82.74, and rating worse than average. 8. Next up is Richmond in Virginia, with a score of 82.80. Rating for this too is worse than average. 7. The rating for all is worse than average, and on number 7 is Raleigh, North Carolina, with scoring of 82.87. 6. Little Rock in Arkansas scored 82.94.5. Memphis in Tennessee scored 83.50.4. At number 4 is Tulsa in Oklahoma with allergy score of 84.16. 3. For the top 3, we again have Oklahoma with Oklahoma City with allergy score of 86.05. 2. Top 2 is New Orleans in Louisiana, scoring 86.81.1. For top 1, Wichita in Kansas has scored an allergy score of 100.00. What Are The Common Allergy Triggers For US?As per the American College of Allergy, Asthma, & Immunology, in many parts of the United States, spring allergies kick off as early as February and can last through early summer. Tree pollen is typically the first to appear, followed by grass pollen later in the season, and then ragweed, which dominates in late summer and fall. In tropical regions, grass pollen can linger for much of the year. Warmer winter temperatures may trigger early pollination, while a rainy spring often leads to fast plant growth and a spike in mold—prolonging allergy symptoms well into the fall.Ragweed: The Top Fall AllergenRagweed is the most common cause of fall allergies. It grows wild across the U.S., especially along the East Coast and throughout the Midwest. Ragweed typically starts releasing pollen in August and continues through November, with levels peaking in early to mid-September in many regions.Other Plants That Trigger Fall AllergiesBurning bushCockleburLamb’s-quartersPigweedSagebrush and mugwortTumbleweed and Russian thistleWhat Affects Allergy SeverityThe intensity and timing of allergy seasons can vary by location, but several climate-related factors play a role in how severe your symptoms may be:Tree, grass, and ragweed pollens flourish in cool nights and warm days.Mold thrives in hot, humid conditions.Pollen counts are usually highest in the morning.Rain can wash away pollen, but levels often rise quickly once it stops.Calm, windless days keep allergens low to the ground.Warm, windy days cause pollen counts to spike.