Memorial Day weekend ends with a furnace door wide open: here’s exactly how hot it gets, when the first storms roll in, and what the rest of your week looks like.
If you stepped outside in Sioux Falls this morning and thought the cool air would last, you were wrong. By late morning, bright blue skies and a steady south wind swept warm prairie air across the metro, sending sidewalks and open fields from comfortable to scorching well before lunchtime — and forecasters say the hottest stretch is still ahead.
The National Weather Service has issued a heat outlook for eastern South Dakota, placing Sioux Falls in the bull’s-eye of an 88-degree corridor that holds firm through at least Tuesday. South winds gusting between 20 and 25 mph this afternoon will make the heat feel relentless — the kind of wind that doesn’t cool you down but instead dries you out.
“Tuesday remains the hottest day of the stretch — warm overnight lows near 60° will keep the air feeling more like midsummer than late May across the northern Plains.”
The dry spell stretches well beyond city limits. Communities along the Interstate 29 corridor — including Brookings, Yankton, and Sioux City — along with parts of southwestern Minnesota and northwestern Iowa, will share the same unseasonable warmth. If you’re heading to a lake, campground, or Memorial Day celebration, conditions through midweek are largely favorable, though you’ll want to pack sunscreen and extra water.
The one wild card: isolated thunderstorms are possible late tonight, and again Monday night. The National Weather Service is not forecasting widespread severe weather at this stage, but any storm that fires over open rural areas could produce lightning, gusty winds, and pockets of heavy rain with little warning. Keep an eye on radar if you’re camping or hosting an outdoor event after dark.
A gradual shift arrives by Thursday, when slightly cooler air and increasing moisture bring scattered showers and thunderstorms back into southeastern South Dakota. Forecasters are keeping a close watch on broader Plains storm development later in the week as humidity slowly builds — a sign that the atmosphere is beginning to reload after this dry, baked stretch.
Long-range models continue to favor above-normal temperatures into early June, meaning this isn’t a brief preview of summer — it may be the opening chapter.
