Highest temperature in Sao Paulo on August 7?

Platform comparison

Market context

The real-world event is the **highest temperature recorded at São Paulo–Guarulhos International Airport on 7 August 2026**, with the market paying out on the *Daily Observations* table rather than the summary high/low. With the crowd at **0% YES**, the market is pricing the top-end temperature band as essentially a complete outsider, which leaves the favourite side firmly with the lower Celsius ranges unless the airport station prints an unusually warm afternoon peak.

That pricing sits against a fairly ordinary August backdrop for São Paulo: long-run guides put the city’s winter highs around the mid-20s Celsius, with August typically cool, dry and fairly stable[9][18][19]. On the day itself, published forecasts were clustered near **24–25°C** for the city, with one source showing a **25°C** high and another a **24°C** maximum, alongside low rain chances or only late-day showers[2][5][7]. For handicappers, that makes the mid-20s the consensus lane; the value spot is on a modest overshoot if the airport’s inland microclimate and a bit more sun push the reading a degree or two above the citywide forecast. The contrarian angle is that airport observations can run cooler than city-centre snippets, so the current 0% implies the market is already dismissing the hotter band almost entirely.

The key catalysts are the official observation sequence at the airport station and whether afternoon cloud, wind or rain arrives earlier than forecast. AccuWeather’s São Paulo forecast flagged a mostly cloudy day with a possible afternoon thunderstorm and an orange wind alert, while a local São Paulo briefing still called for a dry, sunny 25°C afternoon[8][2]. That split matters because the resolution source is a station observation table: if the airport stays sunny into the warmest part of the day, the market’s underdog higher band becomes more live; if showers or cloud cap the afternoon, the favourite lower band remains in control.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Sao Paulo on August 7? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

UK Frequently Asked Questions

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Who Will Win. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.