Hay fever sufferers are now enduring symptoms for up to two weeks longer than they did in the 1990s, a new review has revealed, directly attributing the extended misery to the escalating climate crisis. The Lancet Countdown in Europe 2026 report highlights that climate change has "prolonged the pollen season", significantly increasing the duration of exposure to allergens for millions.
The report, published in The Lancet Public Health, details how shifting weather patterns are altering the flowering seasons of plants that release allergenic pollen. Researchers observed an earlier start to the season by one to two weeks for birch, alder, and olive pollen between 2015 and 2024, when compared with the period of 1991 to 2000. Hay fever, an allergic reaction to pollen from trees, grass, and weeds, typically worsens in warm, humid, and windy conditions when pollen counts are highest, usually from late March to September.
