Highest temperature in Hong Kong on July 7?

Platform comparison

Market context

On 7 July 2026, the Hong Kong Observatory will record the highest daily temperature in degrees Celsius for Hong Kong, a single real-world event that determines the outcome of this prediction market. In this context, a YES share pays out if the recorded temperature falls within a specific range the market defines, while a NO share pays out if it falls outside that range. The current crowd-implied probability of 0% for YES suggests traders believe the temperature will not reach the threshold set for that range, likely because historical data shows July highs in Hong Kong typically cluster below that level.

Historical records frame this probability clearly: July 2007 saw the highest monthly mean maximum temperature of 32.9°C, while July 2018 recorded 31.8°C, and recent forecasts for July 2026 predict daily highs between 30°C and 35°C (86°F to 95°F)[2][9]. Even the hottest day in recent weeks reached only 33.2°C (91.9°F) on 24 June 2026, indicating that temperatures rarely breach extreme thresholds in early July[5]. This consistent pattern explains why the market assigns near-zero probability to the YES outcome, as the threshold likely exceeds typical July maxima.

Traders should monitor the Hong Kong Observatory’s daily extract releases, which finalise the “Absolute Daily Max” data once the relevant monthly summary is published[4][6]. The key catalyst is the official confirmation of the 7 July reading, which depends on the Observatory’s standard data validation schedule. Recent reports confirm July 2025 was Hong Kong’s hottest month on record, with the highest number of hot days since 1884, suggesting climate trends may push temperatures higher, though not necessarily beyond the market’s threshold[8]. No external announcements are expected; the sole dependency is the Observatory’s finalized data release.

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

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 Prediction Market 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.

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.