Highest temperature in Hong Kong on July 24?

Platform comparison

Market context

Polymarket is currently pricing this Hong Kong temperature contract at **0% YES**, which means the market is treating a qualifying high on 24 July as essentially unpriced on the current order book. On Polymarket, that price reflects traders buying and selling conditional tokens settled in **USDC** on **Polygon**, with the contract resolving only after the Hong Kong Observatory publishes the final “Absolute Daily Max (deg. C)” in its Daily Extract.

The historical frame is straightforward: Hong Kong in July is typically hot, humid and very wet, with roughly **31 rainy days** and about **296.1 mm** of monthly rainfall, so the market is really about whether the day’s peak temperature lands in a specific Celsius band rather than whether the city is warm at all.[1] Recent Polymarket weather contracts on nearby Hong Kong dates have also shown dispersed pricing across several Celsius ranges, with one example on 22 July leading at **31°C** and **29°C** not far behind, which suggests traders usually anchor around the low-30s rather than extreme heat outcomes.[2]

For a trader, the main catalysts are the Observatory’s observation cycle, any late-day temperature spike before the noon UTC settlement cut-off, and the timing of the Daily Extract publication, because this market cannot resolve until the final figure is posted on the official climate page. The practical dependency is simple: if the Hong Kong Observatory’s maximum for the day prints into the contract’s target band, the conditional token pays out; if the published maximum falls outside it, the position expires worthless.

Sources: 1 · 2

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.

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.

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.