Highest temperature in Hong Kong on July 7?

Platform comparison

Market context

The Hong Kong Observatory’s absolute daily maximum temperature on 7 July 2026 will determine whether the market resolves to 30°C or another range. Today, Polymarket prices the YES contract at $0.45, implying a 44.5% chance that the peak hits exactly 30°C, while the NO side sits at $0.56 with 55.5% probability. This on-chain pricing, settled in USDC on the Polygon network via conditional tokens, reflects immediate trader sentiment rather than abstract climate models.

Historically, July in Hong Kong has seen extreme highs, with the highest monthly mean maximum recorded at 32.9°C in July 2007[5]. Just one year ago, on 7 July 2025, the daily maximum reached 34.3°C, marking the city’s highest daily peak for moderate heat[8]. These precedents suggest that a 30°C threshold is plausible but not guaranteed, framing the current 44.5% probability as a cautious bet against hotter outliers.

Traders should monitor the Hong Kong Observatory’s “Daily Extract” release schedule, which finalises the “Absolute Daily Max (deg. C)” once data is confirmed[4]. Recent forecasts for 7 July 2026 indicate a high of 27–30°C with 80–95% humidity, aligning closely with the market’s 30°C pivot point[7]. Any deviation in official announcements or updates to the climate change trend—currently rising at 0.35°C per decade since 1996[6]—could shift conditional token valuations before the settlement window closes on 2026-07-07T12:00:00Z.

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 Polymarket Scam?. 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 reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.