Lowest temperature in Hong Kong on August 17?

Platform comparison

Market context

On 17 August 2026, the Hong Kong Observatory will record the lowest temperature for that day, measured to one decimal place in Celsius. The market currently prices this contract at 0% YES across all temperature bands, suggesting traders view the settlement data as either unavailable or immaterial at present. This reflects the standard early-stage pricing for weather markets where historical volatility and seasonal patterns have not yet crystallised trader conviction into meaningful conditional token positions on Polygon.

Hong Kong's August temperatures are among the year's most consistent. Historical Observatory data shows absolute daily minimums in mid-August typically range between 25.0°C and 27.5°C, with readings below 24°C exceptionally rare and above 28°C uncommon. The 1961–2020 climate normals for this period show a mean daily minimum of approximately 26.1°C. August sits within the city's peak summer monsoon season, when nocturnal cooling is limited by sustained heat and humidity. Traders should reference the Observatory's published daily climate extremes dataset to calibrate expectations against the specific temperature bands offered in the market's resolution criteria.

The Hong Kong Observatory publishes daily weather extracts and finalised climate data on a standard schedule, typically releasing daily records within 48 hours of observation. Traders should monitor the Observatory's official website for the "Daily Extract" entry for 17 August 2026 once that date passes. Settlement depends entirely on this publication; the market cannot resolve until the Observatory has recorded and published the absolute daily minimum. No advance forecasts or preliminary estimates will trigger settlement—only the finalised Observatory measurement counts.

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 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%.