Highest temperature in Shanghai on August 19?

Platform comparison

Market context

On 19 August 2026, Shanghai will record a daily maximum temperature at Pudong International Airport. This market asks traders to predict which temperature band that figure will fall into. In prediction markets, a YES share pays out if the event occurs as specified; a NO share pays out if it does not. Here, traders are essentially betting on where Shanghai's heat will peak that day, with the settlement tied to Weather Underground's Daily Observations table rather than summary figures—a distinction that matters because the two sources occasionally diverge.

Shanghai's August temperatures are remarkably consistent. Historical data from the past two decades shows daily highs clustering between 32 and 36 degrees Celsius during mid-August, with readings above 37°C occurring roughly once every three to five years during heat waves. The current crowd probability of 0% suggests traders expect the temperature to fall outside whichever range this particular market specifies—likely an extreme threshold. August 2023 saw Shanghai peak at 40.9°C during an exceptional heat event, whilst more typical years produce maxima in the 33–35°C band. Understanding this baseline helps calibrate whether the market's implied probability reflects genuine rarity or simply reflects which temperature band the market has defined as YES.

Traders should monitor China's meteorological forecasts from late July onwards, as summer monsoon patterns and any developing heat domes will shape conditions by mid-August. The China Meteorological Administration publishes extended outlooks roughly two weeks in advance. Real-time tracking of upper-atmosphere pressure systems and sea-surface temperatures in the Western Pacific will signal whether August 2026 develops as a typical year or an outlier.

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 Prediction Market UK, which mirrors the Polymarket order book directly.

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 Prediction Market UK. 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.

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%.