Lowest temperature in Hong Kong on August 9?

Platform comparison

Market context

Hong Kong’s overnight minimum looks firmly elevated heading into the observatory’s final 9 August reading, with the market still pricing a **0% YES** chance on the low end and nearby alternatives clustered around the upper 20s to around 30°C. Recent observed and forecast temperatures remain consistent with a hot, humid August pattern rather than any sharp nocturnal cool-down, so the live question is whether the minimum lands near the centre of the usual range or slips a little lower before dawn. [1][2][15]

That framing matters because Hong Kong’s August climate normally produces mean minimums around **25–27°C**, while the observatory’s August normals put 9 August’s mean minimum at **25.2°C** and mean temperature at **28.6°C**. The monthly summary for August 2024 showed how persistent warmth can push minimums much higher than climatology, with a mean daily minimum of **27.7°C** during an exceptionally hot month. Against that backdrop, a sub-25°C outcome would be unusual, while a minimum in the high 20s would still sit comfortably within the season’s typical warm overnight envelope. [2][11]

Traders should watch the Hong Kong Observatory’s regional weather updates and the timing of the final “Daily Extract”, because this market cannot settle until the 9 August data are published and the “Absolute Daily Min (deg. C)” is finalised. The main dependency is the overnight evolution of cloud, rain, and wind rather than daytime heat; even with a hot day, a brief shower or stronger mixing can trim the minimum, while calm, humid conditions tend to keep it pinned up. The observatory’s climatology page is the settlement source, so any late update to the daily extract matters more than third-party weather apps. [3][18][14]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Lowest temperature in Hong Kong on August 9? 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 Prediction Today, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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%.