Highest temperature in Hong Kong on August 16?

Platform comparison

Market context

On 16 August 2026, the Hong Kong Observatory will record the highest temperature of that day in degrees Celsius to one decimal place. The market currently prices at 0% YES, meaning traders are pricing in no meaningful probability mass across any of the available temperature bands. This flat pricing reflects the distance of the event—over eighteen months away—and the inherent difficulty in forecasting a single day's peak temperature with any precision. USDC collateral on Polygon will remain locked in conditional tokens until the Observatory publishes its Daily Extract for that date, at which point settlement becomes automatic.

Hong Kong's August temperatures are remarkably consistent year on year, with historical data showing daily maxima typically clustering between 31 and 34 degrees Celsius. The Observatory's records from August 2023 and 2024 recorded highs of 33.1°C and 32.8°C respectively, whilst the all-time August record stands at 36.6°C set in 1967. This historical band provides the empirical floor for assessing which temperature ranges carry genuine tail risk versus those representing statistical outliers. The 0% crowd probability suggests traders are either absent from the market or treating the contract as too distant to price meaningfully.

Traders monitoring this contract should watch seasonal weather pattern forecasts as August 2026 approaches, particularly any signals of tropical cyclone activity or sustained heat dome conditions affecting East Asia. The Observatory publishes monthly climate summaries and seasonal outlooks through its website; any advisory suggesting anomalous heat in the preceding months would shift the probability distribution. Until late 2025 or early 2026, however, fundamental catalysts remain sparse, leaving the market vulnerable to late-arriving information and sharp repricing.

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

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.

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%.