Lowest temperature in Hong Kong on August 6?

Platform comparison

Market context

Hong Kong’s early-August minimums are usually pinned in the high-20s Celsius, and the Observatory’s 1991–2020 normals put 6 August’s mean minimum at 26.8°C, with the broader August average around 26.6°C. That seasonal baseline leaves very little room for a genuinely cool outcome, which is why a 0% implied “YES” on a sub-forecasted low looks consistent with climatology rather than a live weather surprise.[1][6][2]

Comparable August data also points the same way: recent Hong Kong August summaries show mean minimums clustering near 27–28°C, while the long-run record low for the month is far below anything typically seen on a single date, underscoring how unusual an abnormally cool reading would need to be. Even during a wetter-than-normal August such as 2024, the month still finished with a mean minimum of 27.7°C, reinforcing that rainfall alone does not usually drag the daily low into an outlier range.[12][3][9]

For traders, the key watchpoints are the Observatory’s daily extract timing and whether any late-morning update, squall line, or tropical disturbance shifts overnight minima before the final “Absolute Daily Min” is published. The market cannot settle until the Hong Kong Observatory posts the final daily data for 6 August, so the practical dependency is simply the release of that extract on the climate portal, not any separate announcement cycle.[14][4][6]

Sources: 1 · 2 · 3 · 4 · 5

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?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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%.