Highest temperature in Shanghai on August 17?

Platform comparison

Market context

Shanghai's highest temperature on 17 August 2026 will be measured at Pudong International Airport Station and resolved against the Daily Observations table on Weather Underground. The crowd currently assigns zero probability to any outcome, suggesting either a technical issue or genuine uncertainty about which temperature band will be recorded on that date.

August in Shanghai typically sees daily highs between 32–35°C, with occasional peaks above 36°C during heat waves. Historical data from the past decade shows that mid-August temperatures rarely fall below 30°C or exceed 38°C at the airport station, establishing a narrow band where most outcomes cluster. The 0% implied probability across all ranges is anomalous given Shanghai's consistent summer heat patterns and suggests the market has not yet calibrated to seasonal norms. Comparable August dates from 2015–2024 show measurable variation within the 32–36°C range, indicating genuine predictive value rather than certainty.

Traders should monitor China's meteorological forecasts from late July onwards, particularly any alerts issued by the China Meteorological Administration regarding heat waves or tropical systems that might affect the Yangtze River Delta region. El Niño or La Niña conditions heading into northern hemisphere summer can shift baseline temperatures by 1–2°C. The resolution mechanism's explicit reliance on Weather Underground's Daily Observations table—rather than summary figures—introduces a minor dependency on that platform's data collection standards at Pudong station, though discrepancies are historically rare.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Who Will Win, which mirrors the Polymarket order book directly.

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.

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

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%.