Highest temperature in Hong Kong on August 18?

Platform comparison

Market context

On 18 August 2026, the Hong Kong Observatory will record a daily maximum temperature in Celsius, which Polymarket currently prices at 0% across all temperature bands. The settlement hinges on the Observatory's official "Absolute Daily Max" figure published in their Daily Extract dataset, measured to one decimal place. Until that data appears on the Observatory's climate information system, the contract cannot resolve, leaving traders in a holding pattern despite the date falling within the next two years.

Hong Kong's August temperatures cluster reliably between 32°C and 35°C, with historical extremes rarely breaching 36°C during this month. The Observatory's records show that August typically brings the year's most consistent heat, driven by the southwest monsoon and proximity to the South China Sea. The 0% crowd probability across all bands suggests either a technical pricing anomaly or that traders are awaiting historical baseline data before committing capital—a common pattern for weather markets settling on specific future dates where no consensus has yet formed around likely ranges.

The key dependency is the Observatory's publication schedule. Data for any given day typically appears within 24–48 hours of the settlement window closing on 18 August at 12:00 UTC. Traders should monitor the Observatory's website directly rather than relying on third-party weather forecasts, as only their official Daily Extract constitutes valid settlement evidence. Conditional token mechanics on Polygon mean positions remain locked until resolution, so early entry carries no advantage over waiting for the actual temperature to be recorded and published.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Scam?, which mirrors the Polymarket order book directly.

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 Scam?. 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%.