Recent short-range model guidance from the National Weather Service and major ensembles shows New York City daytime highs stabilizing in the low-to-mid 80s on May 18 under partly cloudy skies with light northeast flow. This consensus drives the tight clustering around 80–83 °F outcomes, as traders weigh small differences in cloud timing and boundary-layer mixing that can shift the daily maximum by a degree or two. Historical May climatology places average Central Park highs near 72 °F, so current warmth reflects a transient warm-air advection pattern rather than seasonal norms. The market’s slight edge for 82–83 °F reflects model agreement on peak readings before any late-day sea-breeze cooling, while spread across adjacent bins captures remaining uncertainty in final observed values from official stations.