Highest temperature in Shanghai on July 21?

Platform comparison

Market context

Shanghai is set to record its peak daily heat on 21 July 2026 at the Pudong International Airport station, with the market resolving to the specific Celsius range containing that maximum. The current 0% implied probability for a “YES” outcome is a misnomer, as this binary framing likely masks a multi-outcome structure where traders are instead pricing specific temperature bands. Historical July data shows Shanghai routinely hits highs between 33°C and 38°C, with recent conditions today already reaching 38°C maximum at Pudong, suggesting the 0% figure reflects a misunderstanding of the market’s resolution logic rather than a genuine belief in an impossible event [1][4].

For a programmatic trader, the key is to script a monitor against the Wunderground daily history feed for ZSPD, pulling the exact 24-hour maximum at 12:00Z settlement. The primary catalyst is the absence of significant monsoon disruption or extreme cloud cover, which would suppress temperatures below the 34°C front-runner; conversely, a clear, humid day typical of mid-summer Shanghai will push readings toward 36–38°C. Recent weather guidance confirms July 2026 remains hot and muggy with sunny intervals, reinforcing the likelihood of temperatures exceeding 34°C, the current market favourite [3][4]. Traders should watch for any sudden rain or thunderstorm alerts in the Pudong area, as these are the only realistic dependencies that could shift the outcome to a lower band.

Sources: 1 · 2 · 3 · 4

Methodology

We track Highest temperature in Shanghai on July 21? 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 Polymarket Review 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'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.