Mid-May climatology in Hong Kong, driven by persistent subtropical high pressure over the South China Sea, typically produces overnight minima of 24–26°C as measured by the Hong Kong Observatory. Current model consensus from global ensembles shows limited variability in surface winds and humidity, with radiative cooling moderated by moderate cloud cover and southeasterly flow that prevents sharp drops. Traders assign nearly equal weight to 24°C, 25°C, and 26°C because small differences in the timing of any weak trough or diurnal temperature range can shift the exact minimum by 1–2°C. Seasonal forecasts indicating normal-to-above-normal temperatures reinforce this tight clustering, while the low probabilities on extremes reflect the rarity of significant cold-air intrusions or clear, calm nights this late in the spring transition.