Recent National Weather Service guidance and GFS/ECMWF ensemble means highlight substantial uncertainty for New York City’s overnight low on May 20, with projections spanning the low 50s under post-frontal cool air and light northwest winds to the upper 50s or warmer if southerly flow and cloud cover limit radiational cooling. This spread directly supports the market’s emphasis on outcomes at or below 63°F alongside elevated probabilities for much warmer minima near or above 82°F, reflecting divergent model solutions on steering patterns and boundary-layer mixing. Historical mid-May climatology centers overnight lows near 53°F at Central Park, yet the current four-day outlook shows a transition from cooler conditions earlier in the period toward potentially milder air by midweek. Updated short-range model runs and official NWS briefings expected over the next 48 hours will narrow the range and influence further shifts in trader positioning.