Highest temperature in Hong Kong on August 17?

Platform comparison

Market context

On 17 August 2026, the Hong Kong Observatory will record a single daily maximum temperature in Celsius, rounded to one decimal place. Polymarket currently prices all outcome ranges at 0%, reflecting either a technical listing issue or extremely early-stage liquidity before meaningful trading volume arrives. The settlement mechanism depends entirely on the Observatory's published "Absolute Daily Max" figure in their Daily Extract database, which typically becomes available within days of the observation date.

Hong Kong's August temperatures cluster reliably between 32°C and 35°C, with historical daily maxima rarely exceeding 36°C even during the most intense heat waves. The 17th falls mid-monsoon season, when afternoon thunderstorms frequently interrupt sustained heating. Comparable August dates from recent years show the Observatory recording highs of 33–34°C on roughly two-thirds of days, with outlier extremes above 35°C occurring perhaps once per decade. The current 0% crowd probability suggests traders are either awaiting range options to appear on-chain or treating this as a placeholder contract pending proper USDC liquidity on Polygon.

Traders monitoring this market should track the Hong Kong Meteorological Department's seasonal forecasts released in July 2026, which typically flag anticipated heat episodes weeks in advance. Real-time catalysts include the position of the Pacific subtropical high-pressure system in early-to-mid August and any tropical cyclone activity that might suppress afternoon temperatures. The settlement window closes at 12:00 UTC on 17 August, though the Observatory's final data publication may lag by several days, delaying conditional token resolution until the "Daily Extract" is formally updated.

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

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 Scam?. 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%.