Highest temperature in Sao Paulo on July 6?

Platform comparison

Market context

The 0% YES probability for the highest temperature in São Paulo on July 6, 2026, reflects a sudden shift in the last 48 hours where forecast models have cooled significantly, moving away from the extreme heatwave that previously gripped Brazil. While Rio de Janeiro recently saw a perceived temperature of 62.3°C and an actual peak of 42°C, São Paulo’s July outlook has stabilised into a much milder pattern, with daily highs now expected between 18°C and 22°C rather than the scorching figures seen earlier in the year[3]. This rapid cooling suggests the market is correctly pricing in a return to seasonal norms rather than an anomaly.

Historical data for early July in São Paulo consistently frames afternoon highs in the 18°C to 22°C range, with the most common readings clustering around 20°C to 21°C[3]. The average high for the entire month sits at 23°C, while the warmest day typically occurs on July 3, averaging 22.7°C[8]. These comparable cases indicate that a temperature exceeding the current implied threshold is statistically improbable, reinforcing the 0% probability as a rational assessment of the region’s typical winter-summer transition climate.

Traders should monitor the incoming rain forecasts for the coming days, as meteorological officials have confirmed that temperatures are expected to ease from Wednesday onwards[4]. The primary catalyst is the scheduled arrival of precipitation, which will suppress any residual heat buildup and ensure the day remains within the cool historical average. No further heatwave announcements are anticipated, and the dependency on the Wunderground resolution source will simply confirm these standard, low-temperature readings for the Guarulhos station[1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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.

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.