Latest National Weather Service guidance and ensemble means from the GFS and ECMWF models indicate an overnight low near 52–56 °F at LaGuardia and Central Park on May 20, driven by clear to partly cloudy skies that enhance radiative cooling under a weakening high-pressure ridge. This setup favors the 63 °F-or-below outcome at 48 % implied probability, while warmer marine air advection could push readings into the upper 50s or low 60s. Historical mid-May climatology shows typical lows near 55 °F, providing context for why traders assign meaningful weight to the 82 °F-or-higher bin at 34 % if a stronger southerly flow develops. Upcoming 00Z and 12Z model runs, plus any shift in the 500 mb pattern, will be the next key catalysts for movement in these probabilities.