Traders have converged on a near-certain outcome for an 88°F or higher daily maximum in Houston on May 16 because official National Weather Service observations at primary stations, including Houston Hobby and Intercontinental airports, recorded a peak temperature meeting or exceeding that threshold. Persistent southerly flow and clear skies under a strong subtropical ridge allowed temperatures to climb well above the 1991-2020 climatological normal of 87°F for the date, with afternoon heat indices further amplified by high humidity. Model guidance from the prior week had already signaled this warm anomaly, and no late-day cooling from sea-breeze or convection materialized to alter the outcome. The only realistic scenario that could have challenged the market would have been an unexpected cold-front passage or widespread cloud cover suppressing insolation, neither of which occurred.