Forecasts for Chicago on August 25, 2026, show highs clustered around 77–81°F under mostly sunny to partly cloudy skies with light southerly winds and minimal precipitation risk. National Weather Service guidance and ensemble models indicate modest daytime heating beneath high pressure, with temperatures slightly below the long-term average high of ~82°F. Key uncertainties center on exact peak timing, lake-breeze modulation near the official observation sites, and small differences among model runs for boundary-layer mixing. This spread supports the market’s near-even distribution across the 76–85°F bins, as traders weigh the potential for a degree or two of additional warming or suppression against stable synoptic conditions.