Highest temperature in Sao Paulo on June 13?

On Polymarket, traders set the odds by buying and selling shares of competing outcomes. On Polymarket, prices reflect that venue's order book, liquidity, and how traders price the outcome right now. The top outcome—whether the highest temperature will be 27°C or higher—is priced continuously as traders adjust their positions based on new weather data, model updates, and their own expectations. Share prices range from 0 to 1 and directly represent the implied probability; a price of 0.50 means the market assigns equal odds to both sides. Liquidity and trading volume influence how quickly prices respond to new information.

This market resolves around Jun 13, 2026, once the highest temperature recorded in São Paulo for June 13 is verifiable from credible public sources. The outcome is determined by comparing the official daily high against the 27°C threshold. If the temperature reaches or exceeds that level, the affirmative outcome wins; otherwise, the negative outcome is confirmed. Resolution typically occurs within hours of the market close date, once meteorological data is finalized and published.

Weather model updates and extended forecasts are primary drivers—shifts in atmospheric pressure systems, tropical weather patterns, or seasonal anomalies can significantly alter trader expectations. Real-time satellite imagery and short-term radar data in the days leading up to June 13 often trigger sharp price movements. Urban heat island effects, local pollution levels, and unexpected weather systems (such as cold fronts or moisture surges) can also influence outcomes. As the event date approaches, intraday forecasts become increasingly precise, typically narrowing the range of plausible outcomes and stabilizing prices.