Highest temperature in Hong Kong on August 10?

Platform comparison

Market context

Polymarket prices this Hong Kong heat contract at **0% YES** today, so the crowd is treating a qualifying outcome as effectively impossible and the on-chain position on Polygon, settled in USDC through conditional tokens, is trading as a near-zero event rather than a live weather call. The market resolves against the Hong Kong Observatory’s *Absolute Daily Max (deg. C)* for 10 August, so the only number that matters is the Observatory’s final published daily extract, not a private forecast or airport reading.

That zero price sits against a recent run of extreme heat in the city. The Hong Kong Observatory said the maximum at the Observatory reached **34.4°C on 10 August 2025**, while Hong Kong also saw **36.8°C on 9 August 2026**, described in local coverage as the hottest day ever recorded at the Observatory since records began in 1884. The Observatory’s August normals are far lower, with the 10 August daily normal maximum around **31.1°C**, which helps explain why the contract can only pay if a very hot reading is confirmed in the official record. [1][3][5][15]

For traders, the key catalysts are the Observatory’s hourly readings, any late-day spike before the local day closes, and the publication timing of the final Daily Extract that freezes the settlement input. Forecast pages ahead of 10 August have pointed to highs in the mid- to upper-30s, but the market will only care about the final Observatory figure once data is finalised. The practical dependency is simple: if the Observatory publishes a maximum below the relevant outcome band, the YES side stays worthless; if it prints into the band, conditional tokens redeem accordingly. [7][8][9][14]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on August 10? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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.

What does Polymarket cost to trade?

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%.