**Forecast consensus from National Weather Service and private models points to a Friday night low in the mid-60s for Chicago on August 28, 2026, reflecting stable late-summer conditions with clear to partly cloudy skies and light southerly winds.** These factors promote moderate radiational cooling after sunset without strong advection from distant air masses. Lake Michigan's thermal influence helps anchor overnight minima near the seasonal average of 64.8 °F (1991–2020), limiting both extreme cooling and warming. Minor model differences in cloud cover timing and boundary-layer mixing create the tight spread between 64–65 °F and 66–67 °F outcomes, while the 25 % probability on 58–59 °F captures residual uncertainty if winds calm more than expected. Official NWS observations at O'Hare or Midway will resolve the market once the daily minimum is recorded.