Highest temperature in Hong Kong on July 7?

Platform comparison

Market context

On 7 July 2026, Hong Kong will experience its peak daily heat, a real-world event that determines the outcome of a prediction market tracking the highest temperature recorded by the Hong Kong Observatory. The market currently implies a 0% probability of any specific temperature range, a stark divergence from sportsbook lines that typically price July highs between 32°C and 35°C, and from analyst consensus which expects a hot day consistent with seasonal norms. This zero-implied probability suggests either a data gap or a mispricing that traders must scrutinise against historical benchmarks.

Historical data frames this expectation: July 2007 saw the highest monthly mean maximum temperature of 32.9°C, while July 2018 recorded 31.8°C, and recent forecasts for July 2026 predict daily highs ranging from 30°C to 35°C (86°F to 95°F)[3]. The 2023 and 2024 records show consistent heat, with July 2023 being the city’s hottest month on record, featuring the most hot nights and days since 1884[8]. These comparable cases indicate that a 0% implied probability is anomalous, as the climate consistently delivers temperatures well above the threshold for most ranges.

Traders should monitor the Hong Kong Observatory’s “Daily Extract” for finalised data, as the market cannot resolve until this official publication is available[4]. Recent news confirms that July remains the city’s hottest month historically, with the Observatory noting record-breaking heat in 2023[8]. Key catalysts include the release of the absolute daily maximum temperature in degrees Celsius to one decimal place, which will be the sole resolution source. Any delay in this data release or discrepancies between forecast models and observed readings could shift market dynamics significantly.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on July 7? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Best Prediction Markets. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.