Highest temperature in Sao Paulo on July 23?

Platform comparison

Market context

Polymarket has this contract at **0% YES**, which implies the market is pricing the São Paulo–Guarulhos airport station to miss the relevant temperature band for the day’s recorded high on 23 July. In practice, that means traders on Polygon are paying USDC for conditional tokens that settle off the Wunderground history page, so the key question is not whether São Paulo feels warm at midday, but whether the airport station’s *maximum* reading lands inside the specified Celsius range before the settlement window closes.

The historical backdrop is mostly a cool-season one. July is typically one of São Paulo’s milder months, with average highs around **23°C** and lower overnight readings around **12°C**, while recent forecast coverage has pointed to a warmest day in the next two weeks near **32°C** and several days with precipitation risk. That combination usually matters because a modestly warm afternoon can still be capped by cloud cover, rain, or a marine breeze, and the market resolves on the single highest recorded station temperature rather than a daily average.

A trader watching this market would focus on the airport station’s live weather path through the day, especially any afternoon clearing, dry air, or convective burst that could push the maximum upward before the local evening cut-off. The practical dependencies are the Wunderground station update timing, the airport’s local conditions relative to the wider city, and whether rainfall arrives early enough to suppress the high; with 0% implied probability, even a small shift in the observed maximum would matter because conditional-token pricing in a near-zero market can reprice sharply on fresh readings.

Sources: 1 · 2 · 3

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

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 PolyGram. 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'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.

Do I need to KYC for this market?

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

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.