Official NOAA and National Weather Service observations for New York City on May 31 confirmed a daily minimum temperature of 54–55 °F, driving the market to near-certain consensus on that narrow outcome. This reading reflects typical late-spring conditions under moderate high pressure with light winds and clear skies that limited overnight radiational cooling. Historical climatology for the date shows average lows near 58 °F, so the slightly cooler result aligned with short-term model guidance from the prior 48 hours. Minor uncertainty remains around station-specific microclimate differences or final data-quality checks, though such revisions rarely exceed 1–2 °F and would need to shift the value outside the current bin to alter resolution.