Recent National Weather Service and ensemble forecasts indicate Atlanta's daily minimum on September 23 will likely fall in the mid- to upper-60s Fahrenheit as an easterly flow and increased cloud cover associated with scattered showers suppress overnight radiative cooling. Historical climatology places the average low near 63°F, but current model consensus shows a modest warm anomaly relative to that baseline, with lows projected between 64°F and 69°F depending on exact timing of any clearing. This narrow range creates balanced market-implied odds around the 63°F threshold, as small shifts in dewpoint, wind speed, or precipitation timing—common variables in short-range guidance—could push the observed minimum either side of the key level before resolution.