The dominant market consensus at 23°C for Hong Kong’s lowest temperature on May 16 reflects the Hong Kong Observatory’s official overnight minimum forecast, driven by a persistent subtropical high-pressure ridge that suppressed northerly flow and limited radiative cooling under mostly clear skies. In Hong Kong’s subtropical climate during mid-May, typical daily lows stabilize near 23–25°C as the East Asian monsoon transition maintains warm, humid boundary-layer air with minimal diurnal temperature range. This positioning aligns with climatological baselines and recent numerical weather prediction runs showing stable conditions without significant frontal passages or cloud cover to alter the minimum. A realistic challenge would require an unexpected late-model shift toward stronger northerly winds or increased nocturnal cloudiness, though no such revisions materialized in final observations.