Highest temperature in Shanghai on July 23?

Platform comparison

Market context

Polymarket currently prices this Shanghai temperature contract with **36°C** leading at 40%, while **35°C** sits close behind at 35%, so the market is still clustering around a warm but not extreme daytime high for Shanghai Pudong International Airport.[1] Because the market settles on the highest reading recorded at that station on 23 July, the relevant Polymarket position is a conditional token paid in USDC on Polygon, with the final outcome determined by the Wunderground daily history page rather than by citywide averages or general forecasts.[1]

For context, July in Shanghai is typically hot and humid: a weather overview for the city puts a normal July high around 31°C, with rain on roughly 46% of days and average wind near 23.7 kph.[2] Against that backdrop, the current pricing implies traders are expecting a run above the monthly norm, but not necessarily a spike into the upper-30s unless local heat builds strongly at the airport station. The fact that the market’s frontrunner is only a single degree above the next bucket suggests a fairly tight distribution, where small forecast revisions can matter more than broad seasonal averages.[1][2]

The main catalysts for a move today are the short-range forecasts and any morning update to expected heat, cloud cover, or coastal breeze around Pudong, because the contract closes on the highest temperature observed during the settlement window rather than a daily mean. Traders will usually watch whether the airport can get a few hours of strong insolation before marine air or afternoon convection trims the peak, since that is what decides whether the reading lands in 35°C, 36°C, or higher. As the market is now tied to the day’s actual observations, even a modest change in local conditions can matter more than the broader seasonal outlook.[1][2]

Sources: 1 · 2

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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.

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.

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.