Highest temperature in Shanghai on August 10?

Platform comparison

Market context

Shanghai’s **10 August** temperature will be set by the highest reading at Shanghai Pudong International Airport, not by any app’s headline “day high”, so traders should anchor on the airport station rather than citywide summaries. The market’s current **0% YES** implies either a rounding artefact or a broad expectation that the contract’s target temperature band will be missed; that looks at odds with the climatology, where August in Shanghai usually reaches about **32°C** and the 10 August average high is shown in the low-90s Fahrenheit on several weather-history pages.[2][6][16]

Comparable August data suggest the event is usually decided by whether the day clears the low-to-mid 30s Celsius, with recent years frequently posting highs in the high 80s to mid-90s Fahrenheit and occasional hotter spikes.[5][10][13] Wunderground’s Shanghai history page shows a current day high of **82°F** in the latest available snapshot, which is cool relative to the month’s norm and would support a bearish read if similar conditions persist through the settlement window.[8] In other words, the current market price is far below what the seasonal baseline would normally justify, so any meaningful divergence is between the contract’s near-zero implied probability and the warmer climatological expectation, rather than a tight race between yes and no.[2][16]

The main catalysts are the evolving local forecast, typhoon-related rain bands, and the timing of the warmest part of the day, because late-morning to afternoon heating can still shift the maximum even after an unremarkable overnight start. Timeanddate’s Shanghai forecast for 10 August points to **83/78°F** with heavy rain and overcast conditions, while its hour-by-hour history already shows early-morning temperatures around **81–82°F**.[1][14] That forecast, if it holds, would argue for a lower ceiling than typical August heat and helps explain why a trader comparing platforms would likely see no bullish sportsbook-style pricing pressure here, just a stark gap between seasonal norms and the contract’s depressed implied probability.[1][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

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

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.