Highest temperature in Hong Kong on July 3?

Platform comparison

Market context

The real-world event is the daily maximum temperature recorded by the Hong Kong Observatory on 3 July 2026, measured in degrees Celsius to one decimal place. This figure will determine which temperature band resolves the prediction market, with the settlement window closing at 12:00 UTC on 3 July 2026.

Historically, July is Hong Kong’s hottest month, with average highs around 31.8°C (89°F) and daily peaks frequently reaching 33–35°C. In July 2018, the mean maximum was 31.8°C, but individual days exceeded 34°C. Given that the current crowd-implied probability for any specific band is 0% YES, this likely reflects uncertainty about the exact band rather than an expectation of implausibly low temperatures. Programmatically, a trader would script a bot to poll the Hong Kong Observatory’s “Daily Extract” for the “Absolute Daily Max” once finalized, then cross-reference it against live market odds to execute conditional orders before the 12:00 UTC deadline.

Key catalysts include the publication schedule of the Daily Extract, which typically follows 2–3 days after the observation date, and any weather advisories from the Hong Kong Observatory regarding heatwaves or tropical cyclones. A recent forecast from AccuWeather indicates July 2026 highs between 30–35.6°C (86–96°F), with an average of 31.7°C (89°F)[1]. Traders should monitor the Observatory’s climatological updates and any sudden shifts in regional weather patterns, as these directly influence the final recorded maximum. The resolution cannot occur until the data is officially published, making the timing of the Daily Extract a critical dependency for automated strategies.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on July 3? 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 Kalshi Fees. 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.

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.

Do I need to KYC for this market?

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