Highest temperature in Hong Kong on August 4?

Platform comparison

Market context

Hong Kong’s afternoon high on 4 August will be decided by the Hong Kong Observatory’s official daily extract, and the market is effectively betting on whether the day prints a mid- or upper-30s reading in the city’s hottest exposed locations versus a cooler, rain-blunted outcome. With the crowd-implied probability at 0% YES, the market is treating every listed temperature bucket as an underdog, so the immediate handicapper’s read is that the consensus is not merely cautious but pricing in near-certainty that the exact settled range will not be the one being backed.

Historically, August in Hong Kong is a hot, humid month, with typical daytime highs around 31°C and seasonal averages in the high 20s to low 30s, while forecast services for this month show daily highs commonly in the 86°F to 92°F band and frequent rain. That framing matters because the official HKO measure is the day’s absolute maximum, not the citywide average, so a brief sunny interval can still push the reading into the low 30s even when showers dominate much of the day. On that basis, the favourite remains the temperature band around the low 30s, while sub-30°C outcomes are the more defensive, rain-led contrarian angle.[1][8][15]

For catalysts, traders should watch the Hong Kong Observatory’s short-range updates, especially whether rain bands or thunderstorm warnings persist through the afternoon, as those are the main dependencies for suppressing the maximum temperature. HKO’s regional weather pages and monthly climate updates are the relevant official sources, and once the Daily Extract for 4 August is finalised, settlement will follow the published “Absolute Daily Max (deg. C)”. The current value case sits with whichever bucket captures a modest heat build before showers, while the contrarian case is that cloud cover and rain cap the day below the market’s more optimistic temperature bands.[6][14]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on August 4? 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 Who Will Win 2026, 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

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 Who Will Win 2026. 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 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 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.