Latest numerical weather prediction models from the China Meteorological Administration and international ensembles indicate a May 17 high temperature in Beijing most likely settling near 19–20 °C under partly cloudy skies and light southerly flow. These conditions support moderate daytime warming without strong advection or clear-sky amplification, keeping peak readings within a narrow range. Ensemble spread arises mainly from minor differences in simulated cloud cover and boundary-layer mixing, which can shift the afternoon maximum by 1–2 °C. Southerly winds may briefly strengthen after noon, adding a modest warming boost in some runs, while increased afternoon moisture or showers could cap temperatures closer to 19 °C. With outcomes tightly bunched, trader consensus reflects this genuine forecast uncertainty ahead of tomorrow’s official observations.