Lowest temperature in Hong Kong on August 8?

Platform comparison

Market context

Hong Kong’s overnight low on 8 August will be set by the Hong Kong Observatory’s **Absolute Daily Min** reading, expressed to one decimal place and published only once the daily extract is finalised. For market plumbing, that means the outcome is a single timestamped datapoint rather than a live intraday average, so bots and conditional orders should key off the Observatory release rather than model output or app forecasts. At 1 a.m. local time, the Observatory reported **29°C**, with several districts already in the **27–30°C** range, which is consistent with a warm overnight floor rather than an early-cooling setup.[16][17]

For framing the current **0%** crowd price, August in Hong Kong is typically very warm: the long-run normal for 8 August is a **mean minimum of 26.9°C** and a mean temperature of **29.0°C**.[1] The market is also sensitive to whether an unusually cool or wet airmass pushes the dawn minimum down towards the low- to mid-20s, but recent August climate summaries show the city has often remained hot even in rainy years, with August 2024 and 2025 both recording mean minimum temperatures around **27°C**.[10][11] A zero-implied price usually reflects either a belief that the settle band is currently unthreatened or a thin order book rather than a literal impossibility.

The main catalysts are the Observatory’s hourly updates, any tropical-cyclone or heavy-rain changes affecting overnight cloud and wind, and the eventual publication of the Daily Extract that locks in the official minimum.[17] Programmatically, the cleanest approach is to watch the Observatory feed for the final daily table, compare the reported minimum against the market’s settlement bands, and avoid acting on third-party weather apps that can diverge from the official station reading. Tropical-weather headlines can matter because they change cloud cover and nocturnal mixing, but the trade only resolves from the Observatory’s published figure once it is finalised.[6][17]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Lowest temperature in Hong Kong on August 8? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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

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

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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%.