Highest temperature in Sao Paulo on July 9?

Platform comparison

Market context

Sao Paulo’s July 9 high temperature is now locked in at 22°C, with the market assigning a 98% probability to that outcome and effectively ruling out any spike above 23°C[1]. This near-certainty emerged after a sharp 24-hour correction, when traders abandoned earlier hopes of a 23°C reading following the release of updated local forecasts confirming stable, cool winter conditions across the city[1].

Historically, July in São Paulo is the coldest month, with average highs hovering just under 22°C and rarely exceeding 23°C, making the current 98% confidence in 22°C entirely consistent with long-term patterns[4]. Even during Brazil’s recent severe heatwave that pushed Rio’s perceived temperature to 62°C, actual temperatures in São Paulo remained well below 30°C, reinforcing that extreme heat events do not typically translate to the city’s winter climate[5].

Traders should monitor the upcoming three-day rain forecast for São Paulo, which could further suppress temperatures and solidify the 22°C outcome[5]. No major weather announcements or climate schedules are expected to alter this trajectory, as the region remains under the influence of stable Atlantic moisture and cool southern airflows typical of mid-winter. The settlement window closes on 9 July 2026 at 12:00 UTC, with Wunderground serving as the official resolution source[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Sao Paulo on July 9? 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.

FAQ

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 Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

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

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Today trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.