Highest temperature in Sao Paulo on July 23?

Platform comparison

Market context

The latest run of forecasts has turned **cooler and wetter** for São Paulo, with showers expected through the day and highs clustered around **21-24°C**, rather than the upper 20s seen in some earlier outlooks.[1][2][6] For a market that settles on the *highest* temperature at Guarulhos airport, that matters more than the overnight low: if cloud and rain persist, the day’s peak can land well below the city’s typical July ceiling.[1][4]

That is why the current **0% YES** read is easy to understand. July in São Paulo is usually mild, with average daytime highs around **22-23°C** and only occasional pushes towards the upper 20s or low 30s, so a very hot airport reading would be unusual rather than impossible.[4][9][12][15] The recent forecast range still leaves room for a modest midday lift, but not enough to suggest an extreme outcome, especially with higher precipitation odds and limited sunshine.[1][2][13]

A trader watching this market should focus on the **daytime forecast updates** and whether shower timing shifts away from the warmest hours, because even a small clearing can lift the airport maximum several degrees.[1][6][8] The resolution is tied specifically to the **Sao Paulo-Guarulhos International Airport Station** on Wunderground, so airport observations matter more than citywide forecasts, and any late-morning change in cloud cover, rain intensity, or wind direction could still move the peak temperature modestly.[7][8]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Sao Paulo on July 23? 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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

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's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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.