Highest temperature in Chengdu on August 20?

Platform comparison

Market context

On 20 August 2026, the highest temperature recorded at Chengdu Shuangliu International Airport will determine this market's settlement. The contract currently trades at 0% implied probability across all temperature bands on Polygon, suggesting traders believe no outcome has sufficient conviction to price in, or that the market lacks sufficient liquidity to establish meaningful odds. Resolution hinges on Weather Underground's Daily Observations table rather than the Day High & Low summary—a distinction that matters when automated systems and manual readings occasionally diverge.

Chengdu's August climate provides the historical baseline. The city sits in Sichuan Province where summer temperatures routinely exceed 35°C, with historical August highs clustering between 32–38°C at the airport station. The 2023 heat wave pushed readings above 40°C across central China, though Chengdu itself remained slightly cooler than inland regions. These precedents suggest the market's zero probability reflects either extreme confidence in a specific narrow band or genuine uncertainty about which temperature bracket will resolve. Traders should examine historical Weather Underground data for Chengdu's August patterns to calibrate expectations against the resolution source's actual recording methodology.

The settlement window closes 20 August 2026 at 12:00 UTC, giving traders roughly two years to monitor seasonal forecasting updates and any shifts in Chengdu's urban heat profile. China's meteorological agency publishes monthly climate outlooks; watching these reports and any infrastructure changes at Shuangliu Airport (which underwent expansion work recently) could signal whether historical temperature distributions remain reliable. USDC settlement on Polygon means final payouts depend entirely on the Weather Underground data pull at the specified timestamp.

Methodology

We track Highest temperature in Chengdu on August 20? 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

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

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%.