Highest temperature in Chengdu on August 18?

Platform comparison

Market context

On 18 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 Polygon-based conditional tokens, suggesting the crowd assigns negligible likelihood to the specific temperature range this market covers. Resolution hinges on Weather Underground's Daily Observations table rather than the Day High & Low summary—a distinction that matters when station equipment logs micro-variations throughout the day. USDC settlement will follow whichever range captures the peak reading from that primary source.

Chengdu's August climate presents a consistent baseline for calibration. Historical data shows mid-August highs typically range between 28–35°C, with extreme readings above 37°C occurring roughly once per decade during particularly severe heatwaves. The 2022 summer saw Sichuan province experience exceptional heat, with Chengdu recording 40°C on multiple occasions—a reminder that whilst rare, extreme temperatures do materialise. Current market pricing at zero probability suggests traders are either confident the target range sits well outside plausible outcomes, or the range itself is positioned at an outlier threshold.

Traders monitoring this contract should track China's meteorological forecasts as August 2026 approaches. The China Meteorological Administration publishes seasonal outlooks and monthly heat advisories; any official warnings about above-normal temperatures in Sichuan would shift probability calculations. Additionally, El Niño or La Niña conditions influence East Asian summer patterns and could amplify heat intensity. Real-time station data from Shuangliu becomes critical in the final week, as actual atmospheric conditions diverge from seasonal norms.

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

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 Polymarket Scam?. 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%.