Highest temperature in Hong Kong on May 25?

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Active sub-markets

Market context

Hong Kong's maximum daily temperature on 25 May 2026 will be recorded by the Hong Kong Observatory and published in their Daily Extract climate database. The settlement window closes at noon UTC on that date, meaning resolution depends on the Observatory finalising their official measurement—typically available within hours of the observation period ending. Temperature ranges in Hong Kong during late May cluster around 28–32°C, though extremes have reached 35°C or higher during heat waves. The 0% crowd probability suggests either low trading volume or genuine uncertainty about which temperature band will resolve.

Historical May data from the Observatory shows considerable year-to-year variation. Between 2015 and 2024, maximum temperatures on 25 May ranged from 26.8°C to 33.3°C, with most years falling between 29–31°C. Traders assessing this market should reference the Observatory's 30-year climate normals and recent seasonal patterns; late May typically precedes the onset of the Southwest Monsoon, which can suppress temperatures or, conversely, trap heat depending on atmospheric conditions. The 0% reading likely reflects thin order books rather than consensus that no temperature will be recorded.

Catalysts include tropical cyclone activity in the Western Pacific during May, which could dramatically alter local weather patterns, and the broader El Niño or La Niña phase active in early 2026. Traders depositing via Klarna or SEPA should note that book depth on weather markets often improves as settlement approaches; liquidity typically increases 48–72 hours before the resolution window closes, when Observatory forecasts become more precise and traders can hedge positions before finalisation.

Methodology

We track Highest temperature in Hong Kong on May 25? 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

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 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'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, 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.