Recent National Weather Service guidance and ensemble models indicate Atlanta’s overnight low on September 5 will settle in the mid-70s under clear skies and light winds, supporting the market’s tight clustering around the 72–77 °F bins. Radiative cooling is moderated by elevated dew points near 70 °F and residual warmth from daytime highs in the mid-90s, while the urban heat island effect at official observation sites adds 1–2 °F relative to rural analogs. Minor differences among leading outcomes hinge on exact timing of minimum temperatures before sunrise and small variations in boundary-layer mixing; any increase in cloud cover or wind would favor the upper end of the range, whereas stronger decoupling could push readings toward 72–73 °F. Historical September averages near 68 °F underscore how the current warm anomaly keeps sub-70 °F outcomes at low implied probability.