Highest temperature in Hong Kong on July 18?

Platform comparison

Market context

Hong Kong will record a single daily maximum temperature on 18 July 2026, measured to one decimal place by the Hong Kong Observatory and published in their Daily Extract dataset. This figure becomes the settlement value once the Observatory finalises the reading, typically within days of the observation date. The market resolves to whichever temperature band contains that recorded maximum.

July represents the peak of Hong Kong's summer monsoon season, with historical daily maxima consistently ranging between 32–35°C during this period. The Observatory's 30-year climate normals show a July average daily maximum of 32.9°C, though individual days frequently exceed 34°C. Examining comparable July dates from prior years provides calibration: the 0% crowd probability suggests traders are either awaiting baseline climate data or treating this as a placeholder market pending typical seasonal patterns. Automated resolution depends entirely on the Observatory publishing their Daily Extract; markets cannot settle without this official source, creating a hard dependency on their data release schedule.

Traders monitoring this market programmatically should track the Observatory's publication timeline—data typically appears within 48 hours of the observation date. No weather forecasts or announcements will alter the historical fact once recorded, though pre-market positioning might respond to seasonal anomalies or monsoon intensity reports in early July. Integration with conditional order systems would require flagging the publication date as a resolution trigger rather than treating this as a real-time prediction market.

Methodology

We track Highest temperature in Hong Kong on July 18? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 Polymarket Bot UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Do I need to KYC for this market?

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

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.