Latest forecast guidance from the China Meteorological Administration and global ensemble models indicates Shenzhen's May 18 peak will most likely fall in the 27–29 °C range, reflecting the current balance of a strengthening subtropical high and moderate moisture influx from the South China Sea. Light southerly flow and partial cloud cover are expected to limit daytime heating while keeping humidity elevated, which narrows the plausible daily maximum. The tight clustering of market probabilities around 27 °C (25.5 %), 28 °C (24.5 %), and 29 °C (23.0 %) mirrors the inherent sensitivity of the boundary layer to small differences in cloud timing and precipitation onset, any of which can shift the recorded high by 1–2 °C. Historical May averages near 29 °C provide climatological context, but the present synoptic setup favors the lower end of the typical range.