Highest temperature in Hong Kong on August 5?

Platform comparison

Market context

Hong Kong’s **5 August** high is effectively a one-day temperature call on whether the city prints a cooler, near-average August afternoon or a hotter-than-normal spike. With the market at **0% YES**, the crowd is treating the upper outcome as a near-impossible tail, but the current forecast stack does not support that level of certainty: guidance in the high 20s to low 30s Celsius still leaves room for a final maximum that could land in a few adjacent bands rather than a single nailed-on point estimate.[1][6][17]

For context, Hong Kong in August is usually hot and humid, with long-run daytime maxima around **31°C** and frequent rain interruptions, so the favourite is typically a central band around the low 30s rather than an extreme number.[12][16] The current consensus in the weather market looks more like “warm but capped” than a genuine heat extreme, which leaves the underdog value in whichever outcome best matches the Observatory’s final one-decimal reading if cloud, showers or a late thunderstorm trim the peak.[1][2][17] In handicapper terms, the contrarian angle is that very small shifts in timing — a sunnier mid-afternoon window, or a brief convective burst — can move the published daily maximum by enough to matter when the field is tightly clustered.

Traders should watch the Hong Kong Observatory’s short-range updates, especially the **9-day forecast** and any mention of showers, thunderstorms or tropical-system influences before the noon UTC settlement cut-off and final data publication later.[9][11][17] Recent local reporting has pointed to a wet pattern with showers each day through early August, while still flagging a hotter spell and urban temperatures around **27°C to 32°C** on 5 August, which is the main catalyst for any move away from the current zero-per-cent pricing.[6][13] The key dependency is the Observatory’s final “Daily Extract”, since this market resolves only once the **Absolute Daily Max (deg. C)** for the date is published.[11]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on August 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

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

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.