Highest temperature in Hong Kong on August 9?

Platform comparison

Market context

Polymarket is pricing this Hong Kong Observatory temperature contract around the **36°C** bucket, with the broader market still split between **35°C** and **36°C** outcomes as traders position in USDC on Polygon through conditional tokens. For a user holding shares, the relevant number is not an all-Hong Kong average but the Observatory’s final **Absolute Daily Max (deg. C)** for the city on 9 August, rounded to the published one-decimal reading and then mapped into the contract’s settlement range.

That 0% implied chance on **YES** does not mean the weather cannot be hot; it means the crowd is currently assigning no value to the specific YES side at today’s price. Hong Kong’s August climatology makes the upper 30s plausible in isolated hot spells, but the Observatory’s own August normals for the city centre sit much lower, with a typical daily maximum around the low 30s and a daily mean far below extreme-heat episodes. In comparable recent hot seasons, the Observatory has documented prolonged heat and record-leaning conditions, but the final settlement value still depends on the exact station reading, not on how oppressive the city feels overall.[4][5][16]

The main catalysts for traders are the Observatory’s hourly updates, any hot weather warnings, and the final Daily Extract once the day closes and the value is published. On the morning of 9 August, traders should watch whether the marine layer, cloud cover, or sea breeze interrupts heating before the midday-to-afternoon peak; the market cannot settle until the HKO posts the final figure in its climatological record. That matters mechanically because shares only redeem after the specified condition is confirmed, so any late revision, publication delay, or station update can keep conditional-token holders waiting even after the temperature has effectively been set.[2][11]

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

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 PolyGram. 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%.