Highest temperature in Chengdu on August 9?

Platform comparison

Market context

Chengdu’s **highest temperature** on 9 August is being priced like a complete underdog at **0% implied probability**, but that is much more a reflection of market pricing than of the weather setup itself. August in Chengdu is normally hot and humid, with long-run daily highs around 30–31°C and historical 9 August records above 38°C, so the base rate strongly favours a meaningful positive temperature outcome rather than a near-impossible tail event.[1][16] On the current forecast, Chengdu is expected to reach about **33°C** today, which sits above the long-term 9 August average and in the same broad band as many recent August highs.[1][20]

The relevant comparison set is not whether Chengdu can get hot in August — it clearly can — but whether the specific airport station’s *Daily Observations* table prints a reading that lands in a given settlement range. The all-time August record is **41.6°C** and the 9 August record high cited in historical summaries is **38.1°C**, which shows the location can occasionally run well above the low-30s even if the month’s centre of gravity is closer to the high 20s or low 30s.[1][10][16] That makes the favourite the mid-range temperature bands, while the contrarian angle is that a cloudier or wetter day could cap the top-end reading well below the seasonal ceiling, keeping the extreme upper brackets less likely than the market might assume.[7][9][12]

For traders, the main catalysts are the intra-day observations at Chengdu Shuangliu International Airport, because this market resolves off the station’s *Daily Observations* table rather than the summary high/low box.[3][4] The consensus should continue to track the live hourly print, humidity, cloud cover, and any precipitation, since those factors determine whether the day peaks in the low 30s or stalls nearer the upper 20s.[3][20] There is no obvious external scheduling factor here; the value spots are in the forecast-to-observation gap, especially if the early-morning readings already sit close to the day’s likely ceiling.[1][3]

Sources: 1 · 2 · 3 · 4 · 5

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

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 Who Will Win. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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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?

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