Allergy Seasons Are Becoming Less Distinct Across the Upper Midwest
In the Green Bay-Appleton area and across the upper Midwest, traditional allergy seasons are becoming less distinct and extending throughout the year. Experts attribute the trend to warming temperatures that lengthen pollen seasons, cause tree allergies to start earlier, and…
Green Bay Appleton, WI, October 28, 2026 —
Traditional allergy seasons are becoming less distinct and lasting longer in the Green Bay-Appleton area and across the upper Midwest, according to the trend summary. The change is associated with warming temperatures and is accompanied by reports of year-round allergy symptoms among more people, including some who previously did not experience hay fever.
Experts attribute the longer seasons to several changes in the timing of pollen exposure. Warmer temperatures can lengthen pollen seasons and cause tree allergies to begin earlier. Delayed frosts can also prolong weed seasons, extending a source of seasonal allergens later in the year.
The result is a less clearly defined pattern than traditional allergy seasons, with symptoms reported throughout the year. The trend summary does not provide figures on how many people are affected, how quickly the pattern is changing, or which specific communities have seen the largest increase. It also does not identify the experts or cite particular studies.
Pollution is noted as another factor that may intensify allergens. The summary does not specify which pollutants are involved or explain the mechanism, so the extent of that contribution is not established in the information provided.
The account describes a regional trend but does not include local measurements, dates, or comparisons with earlier years. It also does not provide guidance from health professionals or details about individual cases. What it does identify is a set of connected changes: warming temperatures, earlier tree-allergy timing, delayed frosts that extend weed seasons, and allergy symptoms lasting beyond what people may associate with a distinct season.
Story summarized from the original created by Joel Patenaude on www.wpr.org, see more information here.
