Green Bay, Wis. – Northeast Wisconsin is on the verge of rewriting the weather record books this Friday, as a wave of unseasonable fall heat pushes temperatures to levels not seen in more than a century. Highs are expected to reach the upper 80s and even low 90s across parts of the Fox Valley and central Wisconsin — readings that could topple records dating back as far as 1897.
According to the National Weather Service in Green Bay, forecast highs include 90°F for Green Bay and Stevens Point, both threatening records set more than 100 years ago. Appleton, Oshkosh, and Marshfield are projected near 88–89°F, easily surpassing long-standing October benchmarks from the late 1800s and early 1900s. In all, more than a dozen northeast Wisconsin communities could see their warmest October 4 on record, with temperatures running 25 to 30 degrees above normal.
The heat is being fueled by a persistent ridge of high pressure funneling dry, late-summer air into the region. The National Weather Service warns that records may continue to fall through Saturday night before cooler air filters in from the west. WisDOT advises residents to stay hydrated, check vehicles for overheating, and take precautions during outdoor events or Friday football games as temperatures remain unusually high into the evening.
A gradual cooldown will begin Sunday, returning highs to the 60s and signaling a more seasonable stretch ahead for early next week.
