Highest temperature in Hong Kong on July 4?

Platform comparison

Market context

The Hong Kong Observatory is set to record the absolute daily maximum temperature in degrees Celsius for 4 July 2026, with the market currently implying a 0% chance of any specific range being hit. This binary outcome hinges entirely on whether the recorded peak falls within the narrow band defined by the contract, a scenario that appears statistically improbable given recent climatic patterns.

Historical data from July in Hong Kong reveals that the month is consistently the hottest, with average highs reaching 32°C and record peaks exceeding 35°C[2][3]. Recent observations show temperatures hitting 33.3°C on 2 July 2026, suggesting the 4 July peak will likely align with these elevated summer norms rather than the extreme outliers required for a positive resolution[4]. The 0% implied probability reflects a divergence where sportsbook lines on similar weather contracts often assign non-zero odds to marginal ranges, whereas prediction markets here treat the specific threshold as virtually unattainable based on current analyst consensus.

Traders should monitor the Hong Kong Observatory’s daily extract releases, which finalise the absolute daily max data once the relevant report is published[1][5]. A key catalyst is the scheduled update to the climatological information services, expected to confirm the precise decimal value for the day[8]. Recent reports from the Hong Kong Observatory noting July as the city’s hottest month on record underscore the likelihood of sustained high temperatures, though the specific 4 July figure remains dependent on the finalised extract[9]. No further announcements are anticipated before the settlement window closes on 4 July 2026 at 12:00 UTC.

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

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 Best Prediction Markets UK. 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.

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.