Sioux Falls, S.D. – A sharp autumn chill is setting the tone for the week ahead as brisk winds and plunging temperatures sweep across eastern South Dakota. After a breezy Monday with highs in the 60s, colder air will rush in behind a strong northwest wind, bringing the first widespread frost of the season by Tuesday night into Wednesday morning.
According to the National Weather Service in Sioux Falls, temperatures will fall quickly into the low 30s midweek, marking a significant turn toward early winter conditions. Widespread frost is expected before sunrise Wednesday, especially north and west of the city and along I-90. Forecasters say even sheltered urban areas could see a light frost layer on rooftops and windshields. The agency advises residents to cover tender plants, disconnect garden hoses, and prepare outdoor pets for the coldest morning so far this fall.
Wind gusts near 40 mph Monday will give way to calmer but much colder air. Tuesday’s highs stay in the low 50s under clear skies before dropping below freezing in outlying areas. Sunshine returns Wednesday, but the air will feel crisp and dry — a classic sign of a seasonal shift.
Looking toward the weekend, warmer afternoons return with highs in the 60s, but clear nights will keep the chill around. Long-range models hint that another cold push could arrive early next week, keeping the region on watch for its first fall freeze — a likely turning point toward the true start of winter in the Plains.
Five-Day Forecast for Sioux Falls, SD:
Mon: 63/42 – Breezy with clouds decreasing; gusts up to 40 mph.
Tue: 52/31 – Sunny and cooler; brisk northwest wind.
Wed: 59/33 – Clear and cold; widespread frost early.
Thu: 62/38 – Sunny; frost risk early, then milder.
Fri: 65/42 – Bright and calm; crisp fall day.
