Highest temperature in Shanghai on August 11?

Platform comparison

Market context

Shanghai's highest temperature on 11 August 2026 will be recorded at Pudong International Airport Station and reported via Weather Underground's Daily Observations table. The settlement mechanism explicitly prioritises the granular observation data over summary high-low figures, which matters for edge cases where intraday spikes occur outside peak reporting windows. Traders automating position management should flag the 12:00 UTC cutoff as firm; any temperature recorded after settlement closes will not factor into resolution.

August in Shanghai typically peaks between 32–36°C, with occasional excursions toward 37–38°C during heat waves. Historical data from the past five years shows that extreme readings (above 39°C) occur roughly once per decade in this window, whilst sub-32°C days are rare. The 0% crowd probability suggests the market may be calibrated to a specific temperature threshold—likely in the 38–40°C range—making this useful for traders building conditional orders that trigger only if seasonal forecasts shift materially toward anomalous heat.

Monitor China Meteorological Administration updates and typhoon tracking systems in early August, as tropical systems can either suppress temperatures through cloud cover or intensify heat through pressure dynamics. Weather Underground's API integration allows programmatic polling of historical station data, enabling backtesting against comparable August dates at the same location. Traders should verify data availability 24–48 hours post-settlement; occasional station maintenance or reporting delays have affected resolution timelines on similar weather markets.

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

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

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.

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%.