Highest temperature in Hong Kong on August 1?

Platform comparison

Market context

Polymarket is pricing the contract at **0% YES**, so the implied view is that the Hong Kong Observatory will not publish a highest daily maximum for 1 August 2026 that lands in the market’s YES range once the Daily Extract is finalised. On Polymarket, the position settles in **USDC** via **conditional tokens on Polygon**, so traders are effectively expressing a view on the Observatory’s final one-decimal Celsius reading, not on a generic summer forecast.

For context, Hong Kong’s August climate is typically very warm and humid, with the Observatory’s 1991–2020 normal for 1 August showing a mean maximum of **31.6°C** and a mean temperature of **29.0°C**. Recent HKO seasonal summaries also show how hot the month can run: August 2024 was described as exceptionally hot, with a mean daily maximum of **32.3°C**, while 2025’s August summary again pointed to outbreaks of hot conditions. That backdrop matters because this market is about the day’s *recorded* peak, not the monthly average, so even a small shift in shower activity or cloud cover can move the outcome across a narrow range.[3][6][8]

The main catalysts are the Observatory’s day-of reporting and the later publication of the relevant **Daily Extract**, which is the actual settlement source named by the market. Traders should watch for the HKO’s current weather updates, any late-day thunderstorms or hot-weather warnings that may influence the day’s maximum, and the timing of the extract being finalised, since the contract cannot resolve until that data appears on the Observatory site.[1][3]

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

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

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.

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.