Lowest temperature in Hong Kong on August 10?

Platform comparison

Market context

Hong Kong’s lowest temperature on 10 August will be set by the Hong Kong Observatory’s final “Absolute Daily Min” reading, and the market only resolves once that daily extract is published. With the crowd price at 0% YES, the contract is being treated as a very low-probability event, but the observable weather setup still matters because late-evening showers or a weaker overnight drop can move the day’s minimum by several tenths of a degree.

The historical frame points the other way. Hong Kong’s August normals suggest overnight lows around 26.3°C to 27.0°C, with the 1981–2010 daily normal for 10 August showing a minimum of 26.3°C and the same table putting the month’s typical lows in the high-20s. Independent climate summaries also place average August lows near 26°C to 27°C, while one dataset lists a lowest recorded August temperature of 26.7°C, which shows how rarely the city dips below the mid-20s even in the coolest part of the month. That makes the consensus read for this contract straightforward: unless there is an unusual cool outbreak, the relevant temperature band is likely to sit above the sub-26°C bins.

Traders should watch the Hong Kong Observatory’s morning and midday forecasts, any updated rain or thunderstorm warnings, and the timing of the day’s official Daily Extract publication, because settlement depends on the final archived value rather than an intraday estimate. Short-range guidance from private forecasters has pointed to very warm conditions, with high temperatures around 30°C to 33°C and only scattered shower risk, which is consistent with a high minimum temperature overnight. That leaves the main divergence not between sportsbooks and the market so much as between the market’s near-zero pricing and the climatological baseline, which still implies a central expectation several degrees above freezing points in the contract scale.

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

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.

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.