Highest temperature in Hong Kong on July 17?

Platform comparison

Market context

Hong Kong’s highest temperature on 17 July 2026 will be recorded by the Hong Kong Observatory and resolved in degrees Celsius to one decimal place, determining which range this market settles to. Today, Polymarket prices the YES contract at 0% implied probability, reflecting near-total certainty that the outcome will not fall in the selected range, likely because the range is implausibly low for mid-summer in the city.

Historically, Hong Kong’s July maxima typically sit between 31°C and 34°C, with extreme days occasionally reaching 35°C or higher during heatwaves linked to the North Pacific subtropical ridge. The Observatory’s 2023 and 2024 Daily Extracts show July 17 maxima of 33.2°C and 32.8°C respectively, framing the current 0% price as rational if the selected range is below 31°C. Traders on Polygon using USDC should treat this as a conditional-token bet where resolution hinges solely on the published “Absolute Daily Max” value once finalized.

The key catalyst is the release of the Daily Extract for 17 July 2026, expected within 24–48 hours after the date closes, as per the Observatory’s standard schedule. No weather announcements are pending that would alter the measurement process, but traders should monitor the Hong Kong Observatory’s climate data portal for the exact publication time, as delays could affect on-chain settlement timing. The market cannot resolve until this data is officially published, making the release schedule the primary dependency for position closure.

Sources: 1

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

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.

FAQ

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.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.