Highest temperature in Shanghai on July 31?

Platform comparison

Market context

Shanghai’s **31 July high** will be judged on the highest temperature recorded at Shanghai Pudong International Airport Station, so the live issue is not the citywide average but whether the airport clears a materially hot afternoon. July is normally Shanghai’s hottest month, with average highs around **31–32°C** and frequent humid, rain-prone conditions; airport readings can still sit a little below the city’s inner-core heat, which matters when a market is resolving to a specific station rather than the metropolitan mean.[4][8][14]

The current **0% YES** price looks extreme against Shanghai’s climate history, because late-July Shanghai routinely posts highs in the low-to-mid 30s and the city has recently produced prolonged heatwaves and multi-day stretches above **35°C**.[2][11][17] At the same time, the contract only pays if the airport’s maximum lands inside the relevant temperature band, so even a hot day can miss if cloud, rain, or an onshore breeze trims the top end by a couple of degrees. That gap between headline heat and station-specific settlement is the main reason prediction-market pricing can diverge from broader weather expectations.[3][14][18]

For traders, the key catalysts are the **daytime forecast updates** before the settlement window closes and any late shift in rain, cloud cover, or sea-breeze behaviour over the Pudong coast, all of which can cap the afternoon maximum. The resolution source is Wunderground’s daily history page for Shanghai Pudong International Airport, so the decisive input is the logged daily high there rather than a city bulletin or downtown station reading.[9] In cross-platform terms, sportsbook-style weather lines tend to anchor to rounded city temperatures, while prediction markets and analyst views are more sensitive to the exact station and temperature band, which is where this contract can look mispriced relative to generic Shanghai weather commentary.[9][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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 vs Polymarket. 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.

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.