Highest temperature in Hong Kong on August 11?

Platform comparison

Market context

Polymarket is pricing this Hong Kong temperature contract at **0% YES** right now, so the on-chain USDC/Polygon market is effectively saying the chance of a qualifying top reading is being ignored at current prices. For users holding conditional tokens, the practical question is not whether Hong Kong will feel hot — it is which **one-decimal Celsius band** the Hong Kong Observatory’s published **Absolute Daily Max** will land in once the Daily Extract is finalised. [4][7]

That 0% reading sits against a city that has already been running extremely hot this week. The Observatory reported **36.9°C** on 9 August, a record since 1884, while other districts went even higher, with **39.8°C in Sheung Shui**; that is a useful reminder that the settlement source is the Observatory headquarters figure, not the hottest reading anywhere in the territory. Historical August normals also point to a typical Hong Kong maximum around **31.1°C**, so market outcomes above the low 30s require a meaningful overshoot of seasonal average. [6][9][10][11][2]

For catalysts, traders should watch the Hong Kong Observatory’s hourly readings through the afternoon peak, plus any weather advisories on heat, showers, or tropical system influences that could alter the day’s maximum. Polymarket’s own market page notes that later revisions to temperatures already published for the settlement window will not count, so the key dependency is the first finalised Daily Extract, not later reporting elsewhere. Recent coverage has already linked the current spell to tropical and heatwave conditions, and the Observatory’s public data page is the source that will decide the contract. [4][5][14][16]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on August 11? 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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 Alternative 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%.