Does your allergy seem to be getting more frequent? No, nothing is wrong with you. A scientific report has found that the allergy season has become longer in more than 170 cities across the U.S.

The reason for this change is the rise in temperatures in 203 U.S. cities since 1970, the new report by Climate Central found.

Yes, it all comes down to climate change, as is the case with most problems these days. Increasing temperatures due to climate change are leading to an earlier spring and later fall, the report found. This gives plants a longer growing season--more than two weeks longer on average--to flower, and release pollen.

"The plants can grow earlier and they can pollinate earlier. Allergies are just getting worse and worse," Dr. Kari Nadeau, chair of environmental health and professor of climate and population studies at Harvard School of Public Health, told ABC News.

In the study, researchers kept track of the number of days between the last day of freezing temperature in January and the first day of freezing temperature in December. Allergy season lengthened on average by more than two weeks, the study found.

The change in the duration of the allergy season varied across cities. For instance, in more than 30 cities, the allergy season stretched by at least a month. One extreme was Reno, Nevada, where the allergy season increased by 99 days. The Western U.S. had the largest increase in allergy seasons by nearly a month, followed by the Southeast, Northeast, Southern, and Central U.S. regions, according to the report.

Moreover, some studies have predicted that the average pollen counts will double in 2040 compared to 2000 levels.

"It's a nonstop onslaught of pollen in the air and the duration the levels of pollen that we're seeing are higher than ever before", Dr. David Stukus, pediatric allergist and immunologist at Nationwide Children's Hospital, told ABC News.

According to the Centers for Disease Control and Prevention (CDC), 1 in 4 adults and 1 in 5 children in the U.S. suffer from seasonal allergies. The condition affects as many as 60 million people per year in the country. Allergic disorders like seasonal allergic rhinitis (hay fever) and asthma are common in the pollen season.

It may not seem like it, but allergy season has an effect on the economy. According to the American Public Health Association, allergies are responsible for 3.8 million missed work and school days annually.

People suffering from respiratory illnesses like asthma may be more sensitive to pollen. Exposure to pollen has been associated with asthma attacks and increased hospital admissions, as per the CDC.

"This is a major problem, and it will only get worse if we do not limit climate change and limit carbon dioxide production from greenhouse gases," Nadeau said.