Highest temperature in Hong Kong on May 22?

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Market context

Hong Kong’s official afternoon maximum for 22 May is the settlement driver here, with the Hong Kong Observatory’s “Absolute Daily Max (deg. C)” on the daily extract deciding the range. The market is sitting at 0% for a “Yes” outcome, which points to a contract that is already priced as effectively closed in the relevant bucket rather than one where traders see a live upside case. That is broadly consistent with late-May climatology: the Observatory’s records show May can produce very warm days, with the highest monthly mean maximum reaching 32.5°C and several other years above 31°C, but the more typical May high is still several degrees lower.

Comparables suggest the key question is not whether Hong Kong can turn hot, but whether it does so on the specific day and within the settlement cut-off. Seasonal guides put May daytime temperatures around the high 20s Celsius, while recent platform pricing on adjacent Hong Kong temperature contracts has centred in the mid-to-high 20s rather than at the extreme top end. Lines’ recent coverage of the May 15 contract described a 68% price for 29°C or higher, highlighting that short-dated expectations can move materially around weather model updates and recent observations, yet those same levels still leave substantial room below the hottest historical May readings. The current 0% crowd view therefore looks materially more pessimistic than the sort of mid-range pricing seen on nearby dates, and far below climatological extremes.

Traders should watch the Observatory’s final daily extract and any near-term forecast shifts before the midday UTC settlement window closes. In practice, the main dependency is the Hong Kong Observatory’s official station data rather than any local headline or market commentary, so a late rise in the city’s forecast maximum is only relevant if it is reflected in the final recorded absolute daily maximum. Any divergence between sportsbook-style weather lines, prediction-market pricing, and analyst consensus is likely to be narrow at this stage, because the contract resolves on one exact published figure, not on a broader warm-day theme.

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). 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

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?

On PolyGram, 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.

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 PolyGram?

Zero. PolyGram 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.