Highest temperature in Hong Kong on May 22?

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Market context

Hong Kong’s top recorded temperature on 22 May will be set by the Hong Kong Observatory’s final daily extract, measured in Celsius at the observatory station. With the settlement window ending at 12:00 UTC, this is a narrow daytime weather read rather than a full-day climate estimate, so late-morning heat, cloud cover and any passing showers matter more than the month’s average conditions. May in Hong Kong is typically warm and humid, but the day-to-day spread is wide: climatology points to highs around the high 20s to low 30s Celsius, while the Observatory’s May records show that unusually hot days can run well above 31°C.

The current 0% crowd-implied probability for a YES outcome should be read against how these markets usually price weather files: traders often wait for the Observatory’s observed maximum, and very small changes in the hour-by-hour forecast can move the relevant temperature band quickly. Comparable Hong Kong temperature markets have tended to hinge on whether the city breaks into the low 30s, rather than on the broader seasonal average. For accessibility, the no-KYC up to $1,500 threshold is what matters here: it indicates a low-friction entry point for smaller positions, but it does not alter how the market resolves. German GlüStV and US CFTC reach are relevant because prediction markets can face different treatment depending on where the user is located, even when the event itself is weather-based.

The main catalysts are the Hong Kong Observatory’s late-morning observations, any updated local forecast discussion, and whether a front, showers or stronger sunshine changes the day’s peak before the noon UTC cut-off. Traders will also watch whether the “Absolute Daily Max (deg. C)” is finalised in the daily extract, since that is the source that governs settlement, not a third-party weather app. If the city sits under cloud or rain bands, the ceiling for the maximum temperature is usually lower; if skies clear early, the upper-end bands become more plausible.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on May 22? on the five venues with material liquidity for prediction markets. Live odds come from the Polymarket Polygon order book — the only source that ships real-time data under an open licence. For Kalshi, Betfair and Manifold we list platform attributes (fee, KYC, settlement, payment) instead of fabricated odds, because their APIs use non-comparable contract definitions.

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.

Is this market available outside the US?

PolyGram 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.

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.

Do I need to KYC for this market?

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