Lowest temperature in Hong Kong on August 10?

Platform comparison

Market context

Polymarket is pricing this Hong Kong Observatory contract at **0% YES** today, so the market is effectively saying the lowest temperature on 10 August will not land in the YES bucket and that the USDC-denominated conditional tokens are trading as a near-certain miss. Because settlement uses the Observatory’s final “Absolute Daily Min (deg. C)” for the date, traders are really underwriting the day’s overnight and pre-dawn floor, not the afternoon peak, and the print must appear in the relevant Daily Extract before the market can resolve.[1]

The historical frame is straightforward: August in Hong Kong is usually hot and humid, with the Observatory’s 1981–2010 normals putting 10 August mean minimum temperature at **26.3°C** and mean maximum at **31.1°C**.[3] Recent comparable August readings have also sat in the high 20s, including an Observatory month summary for August 2025 that showed a mean daily minimum of **27.7°C** and a particularly hot 10 August in that year, while a 2024 monthly summary described 10–13 August as showery and thundery rather than notably cool.[13][8] For a market like this, 0% YES usually implies traders see the stated range as requiring an unusually cool reading for mid-August, something that would be well below the climatological norm.[3][13]

The key catalyst is the Hong Kong Observatory’s publication schedule: the market cannot resolve until the final daily extract for 10 August is posted, and any meaningful move will come from the official minimum once the day is closed out.[1] Short-range forecasts published on 10 August point to hot conditions, with AccuWeather showing a low of **85°F** and thunderstorms/showers nearby, while other weather services also describe warm, unsettled weather for the day.[10][14] In practice, traders on Polygon should watch the Observatory update, because once the official minimum is fixed, the conditional token payout settles off that Celsius figure rather than any headline forecast.[1]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Lowest 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 Kalshi UK, which mirrors the Polymarket order book at 0% fees.

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 Kalshi UK. 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%.