Highest temperature in Hong Kong on July 5?

Platform comparison

Market context

On 5 July 2026, the Hong Kong Observatory will record the absolute daily maximum temperature in degrees Celsius, with this market betting on whether that figure falls into a specific range. Today, Polymarket prices the YES side at 0%, implying the crowd sees no chance of the temperature hitting the target range, a stance that demands scrutiny against historical July extremes in Hong Kong.

Historically, July in Hong Kong has seen scorching highs, with the highest monthly mean maximum temperature reaching 32.9°C in 2007, while recent records show temperatures soaring to 39°C in Sheung Shui during an exceptionally hot July day [1][3]. The 0% probability seems to ignore that July is consistently the hottest month, with 2025 alone delivering 53 very hot days and breaking 20 weather records, suggesting that extreme heat is a recurring catalyst rather than an anomaly [10].

Traders must monitor the Hong Kong Observatory’s "Daily Extract" publication schedule, as the market cannot resolve until the finalized "Absolute Daily Max (deg. C)" data is released [4]. Recent news confirms Hong Kong is sweltering through record-breaking heat, with temperatures hitting 34.6°C earlier this year, reinforcing the need to watch for official announcements on extreme heat warnings and the timing of the climatological data release [5]. The on-chain mechanics, settled in USDC on Polygon via conditional tokens, will only trigger once the Observatory confirms the final figure, making the data release the critical dependency for any price movement.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on July 5? 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

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

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 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.

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.