Current forecasts from multiple models indicate overnight lows in Chicago on September 17 will likely settle in the mid-to-upper 60s, with trader consensus clustering on 66–69°F ranges. Persistent northeast winds, increased cloud cover, and elevated dew points near 60°F are limiting radiational cooling under a moderating air mass, preventing a sharper drop toward seasonal norms around 58°F. Recent model consensus shows limited disagreement on these factors through the short-term window, though minor shifts in steering patterns or precipitation timing could nudge readings a degree or two. Updated NWS guidance and next model runs remain key near-term catalysts for any market movement.