Highest temperature in Shanghai on August 3?

Platform comparison

Market context

Polymarket is pricing this Shanghai airport high-temperature contract at **0% YES** right now, which means the market is treating a top reading in the relevant Celsius range as effectively absent despite the city being in peak summer heat. Because the contract resolves to the **highest temperature recorded at Shanghai Pudong International Airport Station** on 3 August, the practical question is whether the day’s maximum slips into the listed band before the settlement window closes at 12:00 UTC. Settlement runs through USDC on Polygon via conditional tokens, so the only number that matters is the Wunderground station maximum for that calendar day.

Comparable August forecasts for Shanghai point to routine heat rather than extremes: AccuWeather’s month view shows daily highs around 82–92°F, while other August guides cluster around the low- to mid-30s Celsius with frequent humidity and rain. For 3 August specifically, several forecasts show highs near 34–35°C and some thunder or showers, which is consistent with a hot but not necessarily record-setting day. That framing helps explain why traders may see the current price as anchored to the wrong side of the range if the contract’s YES band requires a higher threshold than the consensus forecast. [1][2][4][10]

The main catalysts are the day’s actual Shanghai weather evolution, any update to local forecast guidance, and whether thunderstorms or cloud cover suppress the afternoon peak. The Hong Kong government’s China city forecast for 2 August had Shanghai at 29–37°C with cloudy conditions, while AccuWeather’s current Shanghai reading already shows temperatures in the low 30s Celsius with very high heat indices, underscoring how quickly the realised maximum can move if sunshine persists. Traders should watch the airport station observations and the Wunderground daily history page after the settlement cutoff, because a late-morning or early-afternoon spike is the decisive event for this market. [7][14]

Sources: 1 · 2 · 3 · 4 · 5

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 Kalshi 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 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 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.