Current forecast models from the Hong Kong Observatory and multi-model ensembles project a minimum temperature of 24–26°C for May 20, anchoring the closely matched market-implied odds across 24°C, 27°C, and 26°C outcomes. This range aligns with mid-May subtropical climatology, where overnight lows typically hover near 24–25°C under persistent high pressure from the South China Sea. Key differentiating factors include variations in nocturnal radiative cooling, influenced by cloud cover timing and light southerly winds that limit temperature drops, versus clearer skies that could allow a dip toward 23°C. Ensemble guidance shows limited day-to-day variability yet highlights sensitivity to small shifts in humidity and wind speed, which can alter the observed low by 1–2°C. Traders are weighting these near-term model updates ahead of the final observational resolution.