Highest temperature in Hong Kong on August 11?

Platform comparison

Market context

Hong Kong’s 11 August high is a **weather band** market, with the crowd pricing **0% YES** in the sense that the current consensus is effectively that the day will not land in the highest-temperature bucket being traded. The temperature to beat is the Hong Kong Observatory’s final “Absolute Daily Max” for the date, so the key question is not the forecast headline but where the day’s actual peak prints once the day is closed out and the Daily Extract is published.[7][2]

Historically, Hong Kong’s early-to-mid August normals sit in the low 30s Celsius: the Observatory’s 1991–2020 daily normal for 11 August shows an average maximum of **31.1°C**, with high humidity and warm overnight conditions typical of the season.[2] That frames the favourite/underdog split: the market’s consensus is effectively betting on a hot but not extreme outcome, while contrarian value sits in the tail where a stronger-than-expected heat build-up, sun breaks, or late-day heating could push the max into a higher bin than the crowd is discounting. Recent reporting also matters because Hong Kong has already seen extreme heat this season, with the Observatory recording a **36.9°C** all-time high in early August, which reminds traders that very high prints are possible even if they are uncommon.[8][9]

For catalysts, watch the Hong Kong Observatory’s hourly readings, any tropical-cyclone or heavy-rain influence, and the timing of the official Daily Extract publication, because the market cannot resolve until the final data is posted.[7][12] Short-term forecast products point to a hot day with showers and cloud cover in parts of Hong Kong, which can cap the upside if convection arrives early, or leave room for a late surge if clearing occurs after midday.[6][11] In handicapper terms, the favourite remains a mid-30s-style outcome if conditions stay humid and mostly sunny; the underdog/value case is a lower maximum if cloud and showers arrive on schedule, muting the climb into the afternoon.[6][2]

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

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.

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.

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.

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.