Highest temperature in Hong Kong on July 7?

Platform comparison

Market context

The real-world event hinges on whether Hong Kong’s peak temperature on 7 July 2026 reaches the 30°C threshold, a line the crowd currently dismisses with a 0% implied probability for a “YES” outcome. This stark underpricing ignores a decade of escalating heat, where July 2025 alone saw a daily maximum of 34.3°C on the same date, and historical July averages in Hong Kong have frequently breached 32°C, with the highest monthly mean maximum recorded at 32.9°C in 2007[4][5]. The consensus sits firmly on the underdog, assuming a cooler day, yet the value spot lies in the contrarian angle that climate trends—rising at 0.35°C per decade since 1996—make a 30°C+ day statistically probable, not an anomaly[6].

Traders must monitor the Hong Kong Observatory’s daily weather bulletins and the upcoming “Daily Extract” publication, which finalises the official “Absolute Daily Max” figure to one decimal place[2]. Recent reports confirm July 2026 is already tracking as the city’s hottest month on record, with daytime temperatures hitting 33°C and hot days reaching record counts[7]. The key dependency is the Observatory’s data release schedule, typically mid-morning UTC, and any sudden shifts in tropical moisture or monsoon patterns that could suppress or amplify peak heat. With forecasts showing daily highs between 27–31°C for 7 July, the market’s 0% YES probability appears detached from the immediate meteorological reality[2].

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

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

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.

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within 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.