Highest temperature in Hong Kong on August 1?

Platform comparison

Market context

Hong Kong’s highest temperature on 1 August is usually set by a late-morning to mid-afternoon peak, and the climatology for early August points to a hot baseline rather than an outlier-free one. Hong Kong Observatory normals for 1 August show a mean maximum of 31.6°C, while August as a whole has a mean high around 89°F/31.7°C in commercial forecasts, which is why contracts on the upper temperature band are normally priced off the likelihood of a modestly hot day rather than a record-breaker.[3][1]

The current crowd-implied probability of 0% YES looks materially lower than the historical framing would suggest, because Hong Kong has repeatedly posted much hotter Augusts when high-pressure conditions persist. The Observatory’s August 2024 summary described that month as “an exceptionally hot August”, with a mean daily maximum of 32.3°C, and Hong Kong also recorded its hottest August on record in 2023 according to official reporting.[7][6] Against that backdrop, a zero-implied line is difficult to square with both the local climate profile and recent extremes, unless the market is actually anchored to a very high threshold band rather than a routine August maximum.[7][6]

For traders, the key catalyst is not a headline forecast but the Hong Kong Observatory’s day-of observations and the final “Daily Extract”, which is the settlement source and will not be publishable until after the date’s data is finalised.[14] That means the practical inputs are the Observatory’s hourly progression, any tropical cyclone or rain-bearing system affecting cloud cover and rainfall, and whether a late-afternoon peak nudges the official daily maximum above the relevant range boundary. Public forecast services currently cluster around highs in the mid- to low-30s Celsius for early August, which implies any meaningful divergence from sportsbook-style pricing will mostly come from where the contract’s cut-offs sit relative to an ordinary hot-day outcome, not from an expectation of a cold spell.[1][4][8]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on August 1? 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 Best Prediction Markets UK, which mirrors the Polymarket order book at 0% fees.

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

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.

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.