Highest temperature in Hong Kong on July 7?

Platform comparison

Market context

The underlying event is the peak daily temperature recorded by the Hong Kong Observatory on 7 July 2026, measured in Celsius to one decimal place. Current crowd-implied probability sits at 0% for the "YES" outcome, suggesting traders believe the temperature will fall outside the specified range, despite July historically being Hong Kong’s hottest month. This stark pricing contrasts with recent data showing July 2026 daily highs ranging from 86°F to 95°F (approximately 30°C to 35°C), with an average high near 32°C[3].

Historical records frame this probability: the highest monthly mean maximum temperature for July in Hong Kong was 32.9°C in 2007, followed by 32.6°C in 1967, 2014, and 2016[9]. Even in 2018, July’s mean max was 31.8°C, while the city’s hottest July on record saw the most hot days since 1884[8]. These benchmarks indicate that temperatures near 33°C are plausible, making a 0% probability appear aggressive unless the range excludes this realistic band.

Traders should monitor the Hong Kong Observatory’s finalised "Daily Extract" for 7 July 2026, which will publish the absolute daily max once data is confirmed[4]. Dependencies include the release timeline of the monthly weather summary for July 2026, expected in early August[1]. While crypto macro factors like BTC/ETH funding rates or whale flows may influence on-chain liquidity, the contract’s resolution hinges solely on this meteorological data, not market sentiment. Recent news confirms July 2026 is tracking as exceptionally hot, reinforcing the need to watch official updates closely[8]. Settlement occurs in USDC on btc-prediction.bet, with the window closing 2026-07-07T12:00:00Z.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

What are crypto prediction markets?

Crypto prediction markets are on-chain smart contracts where you buy YES or NO shares on a future crypto event (e.g. "BTC above $100k by year-end"). The market price between 0¢ and 100¢ is the implied probability.

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

Can I use Bitcoin directly?

No, Polymarket operates exclusively in USDC on Polygon. You can bridge BTC to USDC via an exchange or bridge service and deposit on Polygon — typically 10-30 minutes processing time.

How does UMA secure the resolution?

The UMA Optimistic Oracle uses a bond system: a proposer posts a bond, a two-hour challenge window opens. On dispute the losing side forfeits the bond — financial incentive for honest resolution.

How volatile are crypto prediction markets?

Crypto markets react to spot prices — a 5% BTC move typically shifts a "BTC above X by date" market 10-20%. Polymarket crypto market liquidity is usually six-figure USD, sufficient for active trading.