Lowest temperature in Hong Kong on August 9?

Platform comparison

Market context

Polymarket is pricing the lowest Hong Kong temperature on 9 August through USDC on Polygon, with the winning temperature band settled by the Hong Kong Observatory’s final **Absolute Daily Min** reading once the Daily Extract is published. The contract is currently trading as a deep outlier at **0% YES** for the broad market framing, which tells a trader the crowd is not expecting the day’s minimum to land in the higher-temperature bands that the market offers. In practical terms, holders of the correct conditional token redeem at settlement; everyone else gets nothing.

The historical backdrop is straightforward: Hong Kong’s August climate is usually very warm and humid, with normals around the mid-to-high 20s Celsius overnight and daily lows commonly above 26°C. The Observatory’s August normals put 9 August’s low around 26.6°C, while other climate references for Hong Kong in August cluster near overnight lows of about 26–27°C and daytime highs around 31–33°C. That means the market’s 0% reading is best read as a strong consensus that the final observed minimum will sit close to the seasonal norm rather than an unusually cool reading.

For traders, the key catalysts are the Observatory’s same-day forecast updates, any thunderstorm or tropical cyclone signalling, and the timing of the final Daily Extract publication, because the market cannot resolve until the data are posted. The HKO forecast page and extended forecast are the main live dependencies, while late-day cloud cover, rainfall, or stronger winds can matter if they suppress the overnight minimum or shift the first hours after midnight. Current public forecast sources are pointing to very hot conditions for 9 August, which reinforces the market’s bias towards a high minimum rather than an outlier cool print.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Lowest temperature in Hong Kong on August 9? 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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

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 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.

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.