Highest temperature in Shanghai on July 23?

Platform comparison

Market context

Shanghai’s daytime high on 23 July will be taken from the Shanghai Pudong International Airport Station record on Wunderground, so the practical task is to track the station’s *maximum* reading rather than citywide averages. July in Shanghai is typically hot and humid, with normal daily highs around 31°C and many guides putting the month’s broader range near 27°C to 36°C, which keeps the settlement buckets in the upper 30s plausible if the heat builds as expected.[1][3]

For a probability read, the current 0% YES looks like a stale or incomplete crowd signal rather than a weather-based call, because the listed market front-runner elsewhere on the venue is 36°C at 40%, with 35°C next at 35%.[2] In a programmatic workflow, that means the useful check is not the headline percentage but the mapping between each price band and the station’s eventual max temperature: if the forecast stack points above 35°C, the upper buckets become the ones to model, whereas a cooler, rain-interrupted day shifts attention back towards the lower 30s.[1][3]

The main catalysts are forecast updates, overnight model shifts, and any early-morning convection around the Shanghai metro, because the market settles on the highest observed temperature during the local day at the airport station. A trader running bots or conditional orders would typically watch the hourly evolution of surface temperature, cloud cover, and rainfall at Pudong, then compare that against the Wunderground history page once readings start printing; on a hot July day, even a brief peak can decide the outcome.[1][3]

Sources: 1 · 2 · 3

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 Polymarket Review UK. 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'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.

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.