Highest temperature in Hong Kong on July 10?

Platform comparison

Market context

Hong Kong is currently experiencing extreme heat, with temperatures reaching 39°C in Sheung Shui and 38.4°C in Yuen Long Park, marking the hottest July day on record for the region[1]. This real-world intensity frames the prediction market for the highest temperature on 10 July 2026, where the crowd-implied probability for a YES outcome sits at 0%, despite recent forecasts suggesting daily highs between 86°F and 93°F (30°C–34°C) for the month[2]. Historical data shows July 2015 held the highest monthly mean temperature at 27.2°C, yet 2025 alone delivered 53 very hot days, indicating a clear upward trend in peak heat events that challenges the current zero-probability stance[4][5].

Traders must monitor the Hong Kong Observatory’s daily extract releases, as the market cannot resolve until the official "Absolute Daily Max" is finalized in the climatological database[6]. The immediate catalyst is the scheduled weather update for 10 July, which currently predicts a range of 28–33°C, though recent records suggest this ceiling may be breached given the 0.35°C per decade warming rate observed since 1996[7][10]. Divergence exists between the 0% crowd probability and analyst lines on platforms like Lines.com, which price the 33°C threshold at 36.5%, highlighting a significant gap in market sentiment regarding whether the current heatwave will persist into the settlement date[9]. The thin volume and 48-hour window further complicate the odds, making this a pure weather forecast call rather than a settled consensus[9].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on July 10? 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

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.

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.