Sagebrush is a common allergen that can make autumn miserable for allergic individuals in dry or mountainous regions. It is a shrub-like weed that is native to western North America, and it generates large amounts of pollen in the late summer and early fall months. August and September are usually the worst allergy months for these plants, but their season can last from early July through the end of October and varies depending on the elevation of the region.
Sagebrush pollen is most prevalent July through October.