Tight odds clustering around 25-27°C stem from ensemble forecasts from ECMWF and GFS models, which converge on a Shenzhen high of 26°C on March 28 amid southerly winds and scattered clouds moderating peak heating. Recent model runs indicate a 1°C dip from prior projections due to rising humidity near the Pearl River Delta, curbing convection and lowering 28°C+ probabilities to 18% combined. Historical late-March averages hover at 24.5°C, but this season's warmer baseline—boosted by residual El Niño influences—elevates mid-20s odds, with urban heat island effects potentially tipping rural model outputs higher. Traders eye afternoon updates from local observatories for resolution-defining hourly maxima.