Trader consensus on the Sao Paulo minimum temperature for September 10 centers on 15–16°C due to closely aligned official station readings near 15°C amid light showers and high humidity that moderated nocturnal radiative cooling. Subtropical spring conditions, with dew points near the air temperature and light easterly winds, limited further drops below this range while urban heat island effects and variable cloud cover introduced minor measurement variability across monitoring sites. Historical September lows average around 12–14°C, but recent model consensus and preliminary airport data from Congonhas and Guarulhos supported the tight 15–16°C bracket. Resolution hinges on final verified minimums from Brazil’s national meteorological service, with any post-event adjustments to hourly observations the key remaining variable.