Highest temperature in Shanghai on August 2?

Platform comparison

Market context

Shanghai’s highest reading on 2 August at Pudong will be judged against a city that is usually hot, humid and capable of strong daily peaks in August. Long-run climate references put Shanghai’s August average highs around 32–33°C, with typical daytime ranges that often sit well into the high 20s and low-to-mid 30s Celsius[2][4][8][14]. For this contract, that means the relevant question is not whether the day gets warm, but whether the afternoon maximum lands in one of the higher temperature bands used by the market’s resolution framework.

The current crowd-implied probability of 0% YES looks detached from the historical profile, because Shanghai has repeatedly posted August highs above 35°C and has recorded extreme heat as high as 41°C in the city’s historical data[2][6]. Recent Shanghai reporting also shows that late-summer heat can persist for long stretches, including a 2025 August run of 26 consecutive days above 35°C[3]. Against that backdrop, a zero-priced YES line suggests either a stale book, a market that is heavily dislocated from weather norms, or pricing that reflects a very narrow target range rather than the broader summer heat regime.

The main catalysts are the actual station observation sequence and the timing of any late-day spike, because the market resolves to the highest temperature recorded during the full day at Shanghai Pudong International Airport Station, not a forecast average[10]. Traders should watch for afternoon heating, cloud cover, rainfall and any typhoon-related disruption, since August in Shanghai is also a rainy, typhoon-influenced month[10][15]. In cross-platform terms, the useful comparison is between the prediction market’s 0% YES and any sportsbook or weather-betting line that prices a high-August outcome; if other venues are leaning towards a normal-to-hot day, this contract is implying an unusually cool or non-resolving scenario by comparison.

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

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

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.

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.

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.