$ 0 0 Series: Climate Science And WisconsinWhat 'Normal' Weather Is Will Be RecalculatedAudio: Shamane MillsWisconsin Public RadioFeb. 10, 2020 | 7 a.m.Shared viaWPRWhat's considered normal weather changes over time. To account for that, the National Weather Service will recalculate a 30-year average of weather patterns from 1991 to 2020.