Highest temperature in Hong Kong on August 6?

Platform comparison

Market context

Hong Kong’s official reading on 6 August will be set by the Hong Kong Observatory’s **Absolute Daily Max** in Celsius to one decimal place, so the market is really a bet on whether the day gets into the low-, mid- or high-30s rather than a coarse “hot or not” outcome.[3][4] The current crowd-implied probability of **0% YES** looks detached from the weather context: private and forecast-style sources for Hong Kong are still pointing to early-August highs around **88–92°F** (about **31–33°C**), with some models showing 6 August near **30°C** and wet conditions.[1][6][7]

That matters because Hong Kong’s August climatology already centres on a mean maximum of **31.6°C** on 6 August, and the city has recently produced much higher readings, including **34.6°C** on the hottest day of the year so far in 2026 and **34.3°C** as a heat record for moderate-heat conditions in 2025.[3][15][18] In practice, sportsbook-style weather lines would usually cluster around the low-30s, while prediction-market pricing at zero implies the contract is being treated as a long-shot extreme heat print; analyst consensus from the available forecast sources is closer to a normal summer outcome than to a sub-30°C day.[1][6][8]

Traders should watch the Hong Kong Observatory’s updates through the day, because the settlement depends on the final published daily extract rather than the live daytime reading.[4] The key catalyst is whether forecast rain bands or thunderstorm activity suppress the afternoon peak; several short-range sources already flag rain or showers on 6 August, which would support a lower maximum even if humidity remains high.[6][7] Since the market cannot resolve until the official data is finalised, any late revision in the Observatory’s daily record is the only figure that matters for settlement.[4]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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 Best Prediction Markets. 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.

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.