Labor Day Weekend Heat: Forecast, Advisories, and When Relief Hits Chicago

Another blistering day is on the books for Friday, with the National Weather Service warning that afternoon heat‑index values could climb into the 100‑to‑110 °F range. A heat advisory is still in effect for DuPage, Kendall, La Salle, Grundy, southern Cook and Will counties, and it won’t lift until 10 p.m. Friday.

That said, the forecast does hint at a breather. Residents north of I‑80 can expect Saturday’s temperatures to dip a few degrees, topping out near the high‑80s. By Sunday and Monday, the mercury should settle into the mid‑80s, giving the relentless humidity a chance to ease its grip.

Rain isn’t a big player this weekend. The service notes a low chance of showers Friday night—mainly a brief, 30 % chance between 1 a.m. and 4 a.m.—and only a 10 % chance of early‑morning thunderstorms on Saturday. Otherwise, it looks to stay dry and mostly sunny.

Friday starts sunny with highs around 92 °F; heat‑index spikes could reach 104 °F. Winds shift from a gentle east‑northeast breeze (5‑15 mph) to a south‑southwest direction, with gusts up to 25 mph. Friday night brings partly cloudy skies, a low near 72 °F and that 30 % chance of brief showers.

Saturday will be mostly sunny, high near 87 °F, heat‑index topping out at about 96 °F. Winds are light, drifting from the northwest to north‑northeast. Overnight, lows drop to the high 60s with a partly cloudy backdrop.

Sunday looks pleasant: mostly sunny, high near 82 °F, gentle east‑northeast breezes, and a low in the mid‑60s. Monday follows suit—sunny, high 82 °F, low around 65 °F—so the weekend should feel markedly more comfortable after the Friday scorch.

Keep an eye on local alerts, stay hydrated, and plan outdoor activities for the cooler morning or evening hours if you’re heading out on Labor Day weekend.