Highest temperature in Hong Kong on July 4?

Platform comparison

Market context

The underlying real-world event is whether Hong Kong’s highest temperature on 4 July 2026 will reach 28°C, as recorded by the Hong Kong Observatory’s “Absolute Daily Max” in degrees Celsius. On Polymarket today, this contract trades at a 0% implied probability for the YES outcome, meaning the market currently believes 28°C will not be hit. The resolution hinges on official data published in the Observatory’s “Daily Extract” after the settlement window closes at 12:00 UTC on 4 July 2026, with temperatures measured to one decimal place.

Historically, July is Hong Kong’s hottest month, with an average high of 89°F (31.7°C) and recorded monthly maxima reaching 35.7°C since 1885[3][6]. Recent data shows a peak of 92.1°F (33.4°C) on 2 July 2026, just two days before the target date[5]. AccuWeather’s July 2026 forecast for Hong Kong indicates daily highs between 86°F and 96°F (30°C–35.6°C), suggesting 28°C is well within the typical range[8]. The current 0% probability appears inconsistent with these historical and forecasted patterns, framing the market as potentially mispriced.

Traders should monitor the Hong Kong Observatory’s “Daily Extract” publication schedule, which finalises data after the settlement window[2][9]. Key catalysts include any official weather announcements or climate bulletins released ahead of 4 July, particularly those detailing heatwave conditions or extreme temperature warnings. The resolution source depends entirely on the Observatory’s verified “Absolute Daily Max” figure, making data integrity and timing critical. No recent news source has contradicted the forecasted high temperatures, reinforcing the expectation that 28°C is likely achievable[8]. Conditional tokens on Polygon, settled in USDC, will reflect the final outcome once the Observatory confirms the temperature.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on July 4? 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

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 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 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.

Do I need to KYC for this market?

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