Highest temperature in Hong Kong on August 11?

Platform comparison

Market context

On 11 August 2026, the Hong Kong Observatory will record the day's highest temperature in degrees Celsius. This market resolves to whichever temperature band contains that single daily maximum reading, sourced from the Observatory's published "Daily Extract" data once finalised. The settlement window closes at midday UTC on that date, though resolution itself depends on the Observatory releasing its official figures—typically available within 24 hours of the observation period ending.

Hong Kong's August temperatures are remarkably consistent year-on-year, with historical daily maxima clustering between 31–34°C during the month. The 0% crowd probability suggests traders are either awaiting the market's full range of outcomes to be specified, or the current implied odds reflect uncertainty about which specific temperature band the market offers. Reviewing the Observatory's climate archives for August across the past decade provides calibration: extreme heat days (35°C+) occur occasionally but remain outliers, whilst readings below 30°C are rare enough to warrant scrutiny of any forecast suggesting them.

For programmatic traders, the key dependency is the Observatory's publication schedule. The organisation typically releases daily climate summaries by 09:00 HKT the following morning, making automated resolution feasible within hours of the settlement window. Conditional orders tied to Observatory data feeds would need to account for potential delays during typhoon season—August falls within Hong Kong's peak tropical cyclone window, and severe weather can disrupt normal reporting cadences. Monitoring the Observatory's website status and cross-referencing with local news sources covering any significant weather events on 10–11 August will signal whether standard publication timelines hold.

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

Is this market available outside the US?

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Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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%.