Highest temperature in Shanghai on August 19?

Platform comparison

Market context

Shanghai's maximum temperature on 19 August 2026 will be measured at Pudong International Airport Station and recorded in Weather Underground's Daily Observations table. The market currently prices this contract at 0% implied probability across all temperature ranges, suggesting traders are either awaiting settlement data or treating this as a placeholder position. On Polygon, this conditional token will resolve to USDC once Weather Underground publishes the official reading, with the specific temperature band determining which outcome token accrues value.

Historical August temperatures in Shanghai provide the baseline for calibrating expectations. The city experiences peak summer heat in mid-August, with average highs around 32–33°C and recorded extremes reaching 40°C in particularly severe years. The 2013 heatwave saw Shanghai record 40.6°C on 6 August, whilst more typical August peaks fall between 34–37°C. These precedents suggest the market's current zero probability across all ranges reflects incomplete data entry rather than genuine uncertainty about whether Shanghai will record *some* temperature on that date.

Traders should monitor China Meteorological Administration forecasts released in early August 2026, which typically provide 10–14 day outlooks with reasonable accuracy for maximum temperatures. Tropical cyclone activity in the Western Pacific during late summer can suppress temperatures significantly, whilst high-pressure systems intensify heat. Weather Underground's station data feeds directly into resolution, so any maintenance or sensor issues at Pudong would be critical to track. The settlement window closes at midday UTC on 19 August, creating a tight window between morning publication and contract resolution.

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 Kalshi UK, 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 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%.