Recent National Weather Service guidance positions a 66–67°F overnight low as the most likely outcome for New York City on May 18, reflecting a stable maritime air mass advecting mild Atlantic air over the region ahead of a weak frontal passage. Ensemble model runs show minimal spread around this range, with limited cooling expected under partly cloudy skies and light southerly flow. This places the implied probability well above historical mid-May normals near 53–55°F at Central Park, driven by the current warm anomaly. Traders are watching the next 12–18 hours for any late-model adjustments or wind shifts that could nudge temperatures into the 64–65°F bin before final LaGuardia observations resolve the market.