Highest temperature in Shanghai on August 9?

Platform comparison

Market context

Polymarket is pricing the Shanghai Airport temperature contract at **0% YES**, which means the market currently assigns no weight to the top daily observation landing inside the resolved Celsius band. The trade settles in **USDC on Polygon** through conditional tokens, so the practical question is not the citywide headline forecast but whether the *single highest reading* in Weather Underground’s **Daily Observations** for Shanghai Pudong International Airport on 9 August 2026 reaches the relevant range before the settlement window closes.

For context, early-August Shanghai typically sits in the low 30s Celsius, with long-run August daytime maxima commonly around **31°C** and some forecasts for this date clustering around the high 20s to low 30s. Several current outlooks point to rain and cloud on 9 August, including AccuWeather’s **85°F** high with periods of rain and Timeanddate’s **84/78°F** extended forecast, while other services still show warmer possibilities nearer **34–36°C**. That spread matters for a temperature-range market because a brief midday spike, even in a wet forecast, can still lift the day’s maximum above the consensus headline if the airport station catches a short-lived warm window.[5][7][9][14][20]

A trader should watch the final pre-settlement forecast updates, especially any change in the timing or intensity of rain, thunderstorms, or wind. Shanghai is in the middle of its humid summer rainy season, so the main dependency is whether convection holds temperatures down at the airport station rather than over the city more broadly. In practical Polymarket terms, the last known price can move on late model runs and station-level observations, but resolution will turn on the Weather Underground daily table for Shanghai Pudong International Airport, not the site’s summary high-low banner.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Shanghai on August 9? 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.

UK Frequently Asked Questions

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 UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.