Highest temperature in Shanghai on August 4?

Platform comparison

Market context

Polymarket is pricing this Shanghai Pudong Airport temperature contract at **0% YES**, so the market is treating a qualifying high on 4 August as effectively absent from the current order book. Because settlement uses the day’s *highest* recorded temperature at Shanghai Pudong International Airport, not the city average, traders are really betting on whether one reading at the station clears the relevant band before the window closes at 12:00 UTC.

For context, Shanghai’s August climate is normally hot enough that a high in the low-to-mid 30s °C is routine rather than exceptional. Current monthly forecasts cluster around highs of roughly 31–34°C, with some models showing 4 August reaching about 33–34°C and little rainfall in the peak daytime hours[1][2][3][8][10][12][15]. That matters for a range-based market: if the contract’s bands are set around typical Shanghai summer heat, the base-rate outcome is an ordinary afternoon maximum rather than a tail event, while a heat spike or an onshore storm can still move the top reading materially.

A trader watching this on Polygon should focus on the same inputs the station will actually see: short-range updates on heat, humidity and any shower or thunderstorm risk, plus the timing of the official Wunderground observation feed. Shanghai’s late-summer weather can swing quickly, with forecasts explicitly flagging patchy rain or thunderstorms even on hot days[3][18]. The practical market mechanics are straightforward: buyers and sellers exchange USDC against conditional tokens, and the eventual payout depends on the resolved temperature bucket, so a late forecast revision or a brief midday spike at Pudong can matter more than the overnight baseline.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Shanghai on August 4? 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

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 Kalshi UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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 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 Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.