Highest temperature in Hong Kong on August 3?

Platform comparison

Market context

Hong Kong’s afternoon peak has trended lower in the latest market pricing, with the crowd still assigning most weight to the 27–28°C band and almost nothing to the low-30s or above. The key move in the last 24–48 hours is that traders have shifted away from a heat-spike scenario and towards a cooler, cloudier outcome for the Observatory’s absolute daily maximum reading.[2]

That pricing sits well below the sort of extremes Hong Kong has printed in recent hot spells. Local reporting this year has already shown the city reaching 34–35°C at the Observatory, while outlying districts have gone several degrees higher during severe heat events.[4][9][11] By contrast, August norms in Hong Kong are usually humid and warm rather than sharply hot, with typical monthly ranges commonly cited around the high-20s to low-30s Celsius, so a 27°C or 28°C result is not an outlier for the season.[5][12]

For traders, the main catalysts are the Hong Kong Observatory’s short-range forecast updates, any changes to rainfall or cloud cover, and how quickly the daily extract is finalised after the observing day. The market resolves only once the Observatory’s “Absolute Daily Max” is published in the relevant daily extract, and the settlement source uses one-decimal Celsius readings, so a small shift in the afternoon maximum can move the outcome between adjacent bands.[6][19] Weather models and official forecasts matter most here because the result is driven by the single highest observed temperature, not the general feel of the day.[3][10]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Hong Kong on August 3? 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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Today 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.