Highest temperature in Hong Kong on May 31?

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Market context

The Hong Kong Observatory will record the single highest temperature reached on 31 May 2026, measured to one decimal place in Celsius. This market resolves to whichever temperature band contains that peak reading, with settlement dependent on official publication of the daily extract data.

Hong Kong's late May climate sits at the threshold between spring and early summer, with historical maxima for this date clustering in the 28–32°C range. The Observatory's records show considerable year-to-year variation; 31 May has seen highs as low as 26.8°C and as high as 33.1°C over recent decades. The current 0% implied probability suggests the crowd has assigned negligible likelihood to certain temperature brackets, likely the extreme upper and lower ranges. Given the natural variability of late-spring weather patterns in the territory, consensus appears to be anchoring heavily toward mid-range outcomes (29–31°C), leaving potential value in moderately warm scenarios (31–33°C) that remain climatologically plausible.

Traders should monitor the broader atmospheric setup developing through May 2026, particularly whether subtropical high-pressure systems establish early or whether monsoon troughs delay their seasonal arrival. Sea-surface temperatures in the South China Sea and any tropical cyclone activity upstream will influence whether Hong Kong experiences typical late-spring warmth or anomalous heat. The settlement window closes at noon UTC on 31 May, giving traders until the Observatory publishes its daily extract—typically released within days of the observation date—to adjust positions based on emerging weather forecasts and real-time conditions.

Methodology

This page is a comparison snapshot: one live quote (Polymarket), four reference venues with their key attributes, and a single execution path — every trade button routes to Who Will Win, which mirrors the Polymarket order book directly.

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

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 it cost to trade on Who Will Win?

Zero. Who Will Win 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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Who Will Win triggers a quick verification flow that finishes in minutes.