Highest temperature in Hong Kong on July 5?

Platform comparison

Market context

On 5 July 2026, the Hong Kong Observatory will record the highest air temperature in degrees Celsius across Hong Kong, a single real-world event that determines the outcome of this prediction market. In this context, a YES share pays out if the temperature falls within a specified range (for example, 30°C to 31°C), while a NO share pays out if it falls outside that range. The current crowd-implied probability of 0% YES suggests traders believe the temperature will not reach the target range, likely due to forecast models indicating a strengthened sea breeze or increased cloud cover that could hold the daily maximum near 30°C[1].

Historical data frames how to interpret this low probability. July is typically Hong Kong’s hottest month, with the highest monthly mean maximum temperature recorded at 32.9°C in July 2007[2]. Extreme heat events have occurred, such as when temperatures reached 39°C in Sheung Shui during Hong Kong’s hottest July day on record[5]. However, the Observatory’s own 30-year averages and recent trends show variability, with the absolute maximum temperature for this year so far being 35.4°C on 30 May[4]. The 0% probability may reflect confidence that 2026 will not match these extremes, possibly due to seasonal weather patterns.

Traders should monitor daily weather forecasts from the Hong Kong Observatory, particularly updates on cloud cover, sea breezes, and humidity levels, as these directly influence peak temperatures[3]. The resolution depends entirely on the finalised “Daily Extract” data published by the Observatory, which is the sole source for the “Absolute Daily Max” value[4]. Recent news highlights that July has been exceptionally hot, with temperatures soaring past 34.6°C earlier this year, prompting hail warnings[10]. Any sudden shift in forecast models or official advisories could alter the market’s implied probability before the settlement window closes on 5 July 2026 at 12:00 UTC.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on July 5? 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

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 Prediction Market UK. 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.

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 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.