Official measurements from Brazil’s Instituto Nacional de Meteorologia (Inmet) at the Mirante de Santana station recorded a daily maximum of 13.6°C on September 7, 2026, with temperatures declining through the afternoon amid a polar air mass and persistent cloud cover. This marked the coldest September afternoon since 2000 and aligned closely with the 14°C outcome now carrying full market-implied probability. The strong consensus stems from verified station data released shortly after the period closed, leaving little room for alternative readings. Scenarios that could still shift resolution include discrepancies between official and unofficial stations, final rounding rules, or post-analysis revisions by meteorological authorities.