Highest temperature in Hong Kong on May 31?

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Market context

On 31 May 2026, the Hong Kong Observatory will record the day's highest temperature in degrees Celsius. Polymarket currently prices this contract at 0%, meaning traders have assigned negligible probability to any single temperature range materialising—a reflection of the settlement window closing at noon UTC on that date, after which historical data becomes fixed. The Observatory publishes daily maximum temperatures to one decimal place through its official climate database, which serves as the binding resolution source.

Hong Kong's May temperatures are historically stable and predictable. Over the past three decades, maximum temperatures on 31 May have typically ranged between 29°C and 33°C, with an average around 31°C. The city's subtropical climate produces consistent late-spring heat patterns, though occasional tropical systems can drive readings higher. The 0% crowd probability reflects not uncertainty about whether a temperature will occur—it certainly will—but rather the fragmentation of probability mass across multiple discrete temperature ranges in the market's structure. Each individual range carries minimal implied probability until traders consolidate positions.

The key dependency is the Hong Kong Observatory's publication schedule. Historical data typically becomes available within 24–48 hours of the observation date, though the market cannot resolve until official figures appear in the Observatory's Daily Extract database. Traders should monitor the Observatory's website in early June 2026 for publication confirmation. No advance forecasts or announcements will materially affect resolution; the outcome is determined solely by actual recorded temperature on the specified date.

Methodology

This page reviews Highest temperature in Hong Kong on May 31? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Polymarket UK — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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 UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 it cost to trade on Polymarket UK?

Zero. Polymarket UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.

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.