Highest temperature in Chengdu on August 9?

Platform comparison

Market context

Chengdu’s highest temperature for 9 August will be set by the **Daily Observations** table at Chengdu Shuangliu International Airport, not the summary high on Weather Underground. That matters for a programmatic approach: a bot should pull the day’s observation feed, normalise Celsius values, and track the maximum printed in the table until the settlement window closes, because the market resolves to the range containing that recorded peak rather than to any forecast or page headline.[3][4]

Historically, 9 August in Chengdu is usually hot but not extreme by local standards. Long-run averages for that date sit around 30.4°C for the high, while WeatherSpark identifies Chengdu Shuangliu International Airport as the relevant proxy station for historical records; the all-time 9 August record on one climate archive is 38.1°C, and August records more broadly can reach the low 40s, so a late-afternoon spike is plausible even when the morning reading is modest.[1][2] The current 0% YES implies the market has not yet priced in that upside, which is common when the observed daytime maximum has not been confirmed.

The key catalysts are the rest-of-day temperature path, any rain or cloud cover that suppresses afternoon heating, and whether the airport station posts a new high before the settlement cut-off. Weather Underground’s history page was already updating in real time this morning, showing a 79°F reading at 9:00 AM and a daily table beneath it, so a trader using alerts or conditional orders would typically watch for each new observation rather than the displayed forecast high.[4][20] Forecast services still point to a warm 33°C-ish day, which leaves room for the market to move if the observed table prints higher than expected.[1][13]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Chengdu on August 9? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Bot UK, which mirrors the Polymarket order book at 0% fees.

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 Polymarket Bot 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%.