Latest ensemble forecasts from leading models including ECMWF IFS and GFS indicate a high temperature near 27°C in São Paulo on April 13, reflecting trader consensus with 39% implied probability for 28°C or higher closely trailed by 30% for exactly 27°C. This positioning stems from a recent cool front on April 10 that capped highs at around 21°C after 27°C on April 9, followed by partial clearing under a weakening high-pressure ridge and light southeasterly winds enhancing sea-breeze moderation. INMET's weekly outlook notes a slight maximum temperature dip of up to 4°C in the Southeast amid low rain chances, but model spread introduces uncertainty from variable afternoon cloudiness and urban heat effects at official stations. New runs expected overnight could refine this before resolution.