Highest temperature in Hong Kong on May 31?

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Active sub-markets

Market context

On 31 May 2026, the Hong Kong Observatory will record the daily maximum temperature in degrees Celsius. This market resolves to whichever temperature band contains that single highest reading, measured to one decimal place and published in the Observatory's official Daily Extract dataset. The settlement window closes at 12:00 UTC on that date, though resolution cannot occur until the Observatory publishes finalised data, typically within days of the observation period.

Hong Kong's late May temperatures cluster reliably between 28°C and 32°C based on thirty-year climate records. The 0% crowd probability suggests traders are either awaiting specific temperature thresholds to be defined or treating this as a placeholder market pending range clarification. Historical May extremes in Hong Kong have reached 35°C on rare occasions, though such readings occur in fewer than 5% of years. The current absence of trading activity reflects uncertainty around which specific temperature bands the market will offer at settlement.

From a regulatory standpoint, this weather derivative falls within different jurisdictional frameworks depending on trader location. The German GlüStV (gambling licensing statute) typically exempts prediction markets on objective, verifiable events like meteorological data, provided operators hold appropriate licences. US CFTC oversight applies if the platform accepts American traders, though weather contracts under $1,500 notional value often escape derivatives classification. The "no-KYC up to $1,500" threshold means traders in certain jurisdictions can access this market without identity verification if their position size remains modest, though platform-specific policies vary. Traders should verify their local regulatory treatment before committing capital.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

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?

On Polymarket Tax UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket Tax 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'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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket Tax UK triggers a quick verification flow that finishes in minutes.