Highest temperature in Hong Kong on June 25?

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Market context

On 25 June 2026, Hong Kong faces a critical heat threshold as the Hong Kong Observatory records the day’s absolute maximum temperature in degrees Celsius. The current crowd-implied probability of 0% for the “YES” outcome suggests traders believe the temperature will fall outside the specified range, despite seasonal forecasts indicating above-normal temperatures for June through August 2026[1]. Historical data shows June highs typically range between 27°C and 33°C, with recent records hitting 34°C at the Observatory and 36.7°C in Sheung Shui on the hottest day of 2026 so far[6]. This precedent frames the 0% probability as a cautious bet against an extreme outlier, rather than a dismissal of rising heat trends.

Traders should monitor the 9-day weather forecast updates from the Hong Kong Observatory, which note an anticyclone aloft driving very hot conditions across Guangdong and Hong Kong[8]. Key catalysts include the finalisation of the “Daily Extract” data, which will confirm the official “Absolute Daily Max” once published. Recent reports from AccuWeather project daily highs between 27°C and 33°C (87°F–93°F) for June 2026, with an average high of 32°C (90°F)[2]. Any deviation above this range—driven by sustained anticyclonic pressure or ENSO-related warming—could shift book depth rapidly, especially as funding flows from deposit rails like Klarna and SEPA continue to fuel market liquidity on platforms such as polymarket-klarna.co.uk.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on June 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 Polymarket Klarna 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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Polymarket Klarna UK 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.