The report ranks the top 100 U.S. cities based on pollen levels, over-the-counter allergy medication use and access to allergists. For three years in a row, Wichita, Kansas, ranks as the most challenging city for pollen allergies. Cities in the South and East are among the hardest hit.

Pollen levels are on the rise across the United States as warm spring weather spreads across the country. And AccuWeather meteorologists warn one area could face a "dual peak" of allergens this year.

When you breathe in pollen, your immune system releases histamine and other inflammatory mediators, triggering common allergy symptoms. Unlike a cold, which typically clears up in a couple of weeks, allergies can last much longer, often starting with a runny nose and progressing to nasal congestion, sinusitis, fatigue and headaches.

Pollen season is starting earlier and ending later as a result of our warmer climate. In a mild winter, the pollen season can actually start in February. Red maple birch and willow are but some of the sources putting out tiny pollen grains. Ash, elm, oak and eventually pine also get into the act.

High levels of alder pollen are likely to continue for another week. Wales, South East England, and both the East and West Midlands are set to encounter a high risk of birch pollen. The grass pollen season is still some weeks off, but experts say tree pollen season can start as early as January.