Highest temperature in Shanghai on June 20?

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Market context

Shanghai Pudong International Airport needs only one afternoon observation to decide this contract: the highest temperature recorded there on 20 June, with settlement based on the Wunderground station history page. In broader climate terms, late June is already deep into Shanghai’s hot season: WeatherSpark puts the airport’s average daily high in June around 77°F to 83°F, with the hot season running from mid-June into mid-September[1][7]. That makes a very low implied chance of the lower temperature buckets easier to understand, but a 0% YES price still looks extreme if the market is treating “YES” as anything above the warmest bands rather than the whole distribution.

Comparable readings in Shanghai also show how quickly the airport can move into the upper 20s or low 30s Celsius once humid air builds in. Climate summaries for Pudong note summer highs regularly above 30°C, and current Shanghai-area reporting has already shown warm, humid conditions this week, with nearby Hongqiao observing 28°C and BBC Weather calling for a high near 31°C[5][4]. By contrast, some short-range airport forecasts have been much cooler, which highlights the gap between average climate, actual day-of-weather, and the specific noon-to-evening peak that determines this market[2][8].

Traders should watch the airport station observations and any late-day thunderstorm or sea-breeze pattern that can cap the maximum temperature before local peak heating. The key dependency is not a headline city forecast but the precise Shanghai Pudong International Airport Station reading on Wunderground through the settlement window; if clouds, rain, or stronger winds arrive in the afternoon, the final high can land several degrees below the regional expectation[2][3][6]. The main cross-platform divergence is therefore between prediction-market pricing at 0% YES and the broader weather evidence, which still supports a meaningful chance of a warm-to-hot reading rather than a near-zero outcome.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Shanghai on June 20? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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

Is this market available outside the US?

Best Prediction Markets is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 it cost to trade on Best Prediction Markets?

Zero. Best Prediction Markets routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.