Official observations from Brazil's Instituto Nacional de Meteorologia (INMET) automatic weather stations and São Paulo airports, including Guarulhos (GRU), confirm the highest temperature on April 29 reached 29°C, typically measured via calibrated thermometers during peak afternoon hours under partly cloudy skies with isolated showers. This aligns with pre-event INMET forecasts projecting maxima of 28–29°C as a departing cold front limited solar heating and atmospheric mixing, capping intensities below seasonal norms for late April. Trader consensus at near-100% implied probability reflects this verified data across multiple sites, embodying skin-in-the-game agreement on resolution criteria. Realistic challenges include post hoc data audits revealing sensor anomalies, though multi-station corroboration makes revisions improbable; final INMET bulletin expected soon.