Short-term forecast models from the National Weather Service show a tight spread in overnight minimum temperatures for Miami on September 22, with ensemble guidance clustering between roughly 72°F and 79°F. This narrow range reflects typical late-September subtropical conditions, where the Atlantic and Gulf moderating influences, combined with variable cloud cover and light wind regimes, limit radiative cooling at night. Sea-breeze circulation and boundary-layer moisture further constrain how low temperatures can drop, while any increase in onshore flow or lingering tropical moisture could nudge readings slightly higher. With no strong frontal passage or major synoptic shift expected in the next 48 hours, traders see comparable likelihood across the central bins, underscoring the inherent uncertainty in pinpointing the exact diurnal minimum at this lead time.