Boise, Idaho Faces Intensified Allergy Season Due to Atmospheric Rivers
Boise, Idaho, has been identified as the worst city in the U.S. for spring allergies in 2026, according to a study by the Asthma and Allergy Foundation of America (AAFA). The report highlights how atmospheric rivers, which are streams of vapor moving inland from the ocean, have contributed to an earlier and more intense pollen season. These atmospheric rivers brought significant rain and humidity to the region in 2025, accelerating plant growth and extending the pollen season. Climate change is cited as a key factor in intensifying these atmospheric rivers, with researchers predicting they will grow 25% larger and lead to 50% more storms and rainfall by the end of the century. Boise, known as the 'City of Trees,' is particularly affected due to its abundance of pollen-producing plants. 
