Lowest temperature in Hong Kong on August 9?

Platform comparison

Market context

Hong Kong’s lowest temperature on 9 August will be set by the Hong Kong Observatory’s final daily extract, and the market is currently pricing that outcome as **29°C** with the crowd implying a near-certain result at 0% for anything else. Polymarket’s contract page shows 29°C at 91%, 28°C at 7%, 27°C at 1.4% and 26°C or lower at under 1%, so the live market is heavily skewed towards an overnight minimum that stays unusually warm even by Hong Kong standards.[10]

That distribution is consistent with climatology for early August. The Observatory’s 1971–2000 normals put 9 August’s mean minimum at 26.2°C, while secondary weather reference pages place typical August lows around the mid-to-high 20s Celsius and note that Hong Kong’s late-summer humidity and tropical air masses often keep nights warm.[2][3][7] In that context, 29°C is not a historical median so much as a forecast-driven extreme, which helps explain why the market still leaves a small tail for 28°C and below despite the dominant crowd view.[10]

The key catalysts are the Observatory’s short-range forecast updates and any change in local weather warnings before the daily minimum is fixed. The resolution source is the HKO “Daily Extract” for 9 August, and the market cannot settle until that data is published, so traders will be watching the timing of the final bulletin as closely as the forecast itself.[10] If official guidance continues to point to very warm overnight conditions, the cross-platform picture should remain aligned: the sportsbook-style line embedded in the market is already far above 28°C, while analyst-style climatology still anchors expectations lower than the current contract price.[2][10]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Lowest temperature in Hong Kong on August 9? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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 PolyGram. 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.

Do I need to KYC for this market?

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