Pollen season generally ends at different times depending on the type of pollen and the region:

• Tree pollen season usually ends by late spring or early summer (May to June), though in some milder regions it may extend into July.
• Grass pollen season typically wraps up by mid-summer (July or August), but can last into early fall in cooler climates.
• Weed pollen season, especially ragweed, tends to be the last to end, often finishing after the first hard frost in late October to early November, but can linger longer in warmer areas.

In many places, pollen counts decrease significantly by September, marking the end of most traditional pollen allergy seasons. However, some weed pollen like ragweed can persist into the fall before finally going away with colder temperatures or frost. Winter generally sees very low pollen counts, though early tree pollens can sometimes appear as early as January in some regions.

Therefore, pollen generally "goes away" by late fall or early winter in most areas, with exact timing depending on local climate and vegetation.