Trader consensus on Polymarket reflects tight uncertainty for São Paulo's May 16 high temperature, with 25–27°C outcomes leading at 28.5–32.0% implied probabilities amid divergent forecast models. INMET's latest guidance projects a conservative 23°C maximum under mostly clear skies, low humidity (30–85%), and light winds, while private forecasters like Climatempo and CNN indicate 25°C, aligned with ECMWF/GFS ensembles showing stronger afternoon heating from high-pressure subsidence. Differentiating factors include potential afternoon cloudiness from an approaching weak front, which could cap peaks at 25°C, versus fuller insolation pushing toward 27°C in the urban heat island of São Paulo—where official stations like Mirante de Santana measure highs. Recent May 15 observations hovered in the low 20s°C, but a warming trend post-cool spell drives the cluster; final model updates tonight could shift odds before resolution via INMET data.