Highest temperature in Hong Kong on August 2?

Platform comparison

Market context

Hong Kong’s maximum temperature on 2 August will be set by the Hong Kong Observatory’s final “Absolute Daily Max” reading, and the market will only resolve once that daily extract is published in the finished record. The current 0% YES price implies traders see no credible path to the selected outcome at present, but the contract is still exposed to late-day weather and to any update in the Observatory’s final figures, which are recorded to one decimal place.

Historically, August in Hong Kong is a high-variance, heat-and-rain month rather than a clean heat bet: recent climatology and commercial forecast pages cluster around the high 20s to low 30s Celsius, with official-style forecasts for early August pointing to roughly 28°C on unsettled days and broad ranges spanning the high 20s to low 30s. That makes any single temperature band sensitive to cloud cover, showers and thunderstorm timing, and it also explains why market pricing on comparable temperature contracts often stays spread across adjacent bins rather than concentrating in one outcome. By contrast, the present 0% crowd price is far below the broad forecast range implied by weather models and the nearby market bands shown on Polymarket, which have centred much of the probability on 27°C and 28°C. [1][3][8]

Traders should watch the Hong Kong Observatory’s morning and midday updates, plus any thunderstorm or rain warnings that could suppress the day’s peak, because the daily maximum is usually driven by whether clearing occurs before the afternoon heating window. Recent local reporting also shows Hong Kong has already logged very hot days in 2026, including readings above 34°C earlier in the summer, which matters only as context: it signals that extreme highs remain possible, but not that they are the base case for 2 August. The practical catalyst is the Observa­tory’s final publication, not mid-day headlines, because the contract resolves on the official daily extract once the data are finalised. [9][13]

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

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

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.

Do I need to KYC for this market?

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