Highest temperature in Hong Kong on June 10?

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Active sub-markets

Market context

On 10 June 2026, the Hong Kong Observatory will record the day's highest temperature in degrees Celsius. That figure, published to one decimal place in the Observatory's official Daily Extract, will determine which temperature band this market resolves to. The settlement window closes at midday UTC on that date, though resolution itself depends on the Observatory finalising and releasing its data, which typically occurs within hours of the observation period ending. Currently, Polymarket prices this contract at 0% YES across all outcome bands, reflecting either a technical lag in pricing or genuine uncertainty about which specific range will contain the recorded maximum.

Hong Kong's June temperatures are remarkably consistent year-on-year. Historical data from the Observatory shows that daily maxima in early June cluster between 28°C and 32°C, with occasional excursions above 33°C during heat waves. The 30-year average high for mid-June sits around 31°C. This seasonal stability means traders can anchor expectations to decades of comparable observations rather than speculating wildly. The 0% probability across all bands suggests the market may not yet have attracted sufficient liquidity to establish meaningful odds, or participants are awaiting clearer range definitions before committing USDC on Polygon.

The key dependency for traders is the Observatory's publication schedule and any unusual weather patterns developing in late May or early June 2026. Tropical cyclone activity, monsoon onset timing, or anomalous heat systems could shift actual temperatures outside the typical range. The Hong Kong Observatory publishes daily climate data on its website within 24 hours of observation; traders should monitor forecasts from mid-May onwards to assess whether conditions are tracking towards historical norms or deviating significantly.

Methodology

We track Highest temperature in Hong Kong on June 10? 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 Polymarket 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.

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 Polymarket UK?

Zero. Polymarket UK routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.