Current National Weather Service and ensemble model guidance for New York City points to an overnight low near 55 °F on May 21, reflecting modest radiative cooling under partly cloudy skies and light southerly flow. Mid-May climatological normals place average Central Park lows between 52–56 °F, so the spread of market-implied probabilities across the 49–61 °F bins captures the typical springtime variability in cloud cover, dew-point depression, and boundary-layer mixing. Updated short-range runs from the GFS and ECMWF will refine wind and moisture forecasts over the next 48 hours, potentially sharpening or broadening the distribution depending on whether clearer skies allow greater nocturnal cooling or Atlantic moisture limits temperature drops.