Forecast models from the National Weather Service show a tight range for New York City’s maximum temperature on May 17, with most guidance projecting afternoon highs between 86 °F and 89 °F under weak southerly flow and partly cloudy skies. Ensemble spreads remain modest, yet small differences in boundary-layer moisture and timing of any sea-breeze front create the near-even split between the 86–87 °F and 88–89 °F bins. Historical May climatology places the long-term average high near 72 °F, so current readings sit well above normal and leave little room for lower outcomes. Traders are watching the 2 p.m. local update for any last adjustments in mixing depth or cloud cover that could shift the final peak by a degree or two before resolution.