Trader consensus on Polymarket has locked in 29°C as the highest temperature in Mexico City on April 17 at 100% implied probability, driven by the official observation from Benito Juárez International Airport's meteorological station, the market's designated resolution source affiliated with Mexico's Servicio Meteorológico Nacional (SMN). This aligns with SMN's pre-event forecast of 28–30°C under a stable high-pressure system, clear skies, and typical mid-April warming trends, where average highs hover around 26°C but often exceed 28°C during dry spells. Realistic challenges would require a data revision from SMN or airport logs—highly unlikely post-validation—or discrepancies in measurement methodology, though historical precedents confirm such readings as final. No further updates expected as the event has passed.