Sioux Falls, South Dakota – 45 mph wind gusts and 15% humidity are accelerating wildfire spread across eastern South Dakota through early evening Saturday, creating extreme fire danger and rapid ignition risk. Conditions intensify quickly from late morning into the afternoon hours.
According to the National Weather Service in Sioux Falls, critical fire weather conditions will peak from early afternoon through early evening, driven by strong south to southwest winds and very low relative humidity. Fire danger begins increasing by mid-morning and remains elevated into the evening across much of eastern South Dakota.
Communities including Sioux Falls, Brookings, Mitchell, Yankton, and Vermillion are facing the highest risk, where wind gusts between 35 and 45 mph align with humidity values dropping into the teens. These conditions allow any spark to spread quickly, especially along open fields, roadways, and agricultural land.
Travelers along I-29 and I-90 corridors should remain alert for reduced visibility if fires ignite near roadways. Outdoor burning is strongly discouraged, and residents should avoid activities that could create sparks, including equipment use and towing chains. Fire crews warn that containment could become difficult during peak afternoon winds.
The most dangerous window will ease after sunset as winds weaken and humidity recovers. However, fire danger remains elevated into Sunday, and additional advisories are possible as dry and windy conditions persist.
