Highest temperature in Hong Kong on August 10?

Platform comparison

Market context

Hong Kong’s hottest reading on 10 August will be set by the Hong Kong Observatory’s final **Absolute Daily Max** figure, published later in its Daily Extract, not by live market estimates or off-site stations. The reference point is the Observatory headquarters, and the market will only resolve once the official daily data are finalised in Celsius to one decimal place.

The current crowd-implied **0% YES** looks mainly like a liquidity and timing artefact rather than a strong directional view, especially on a date that can still move sharply with tropical-cyclone subsidence, stalled showers or a late-afternoon spike. Hong Kong has just logged an extreme benchmark: the Observatory reported **36.9°C on 9 August 2026**, the city’s hottest day on record since observations began in 1884, with some districts nearing 40°C under Typhoon Dolphin’s influence.[1][10][15] That makes the upper temperature bands more credible than a typical August day, even though the long-run normal for 10 August is much lower, with a mean maximum of about **31.4°C**.[5]

On platform mechanics, Polymarket shows the event as multi-outcome temperature bands with prices that map directly to implied probability, whereas Kalshi-style markets usually quote the same idea in cents and settle per contract face value; Smarkets and Betfair typically present decimal odds, so the same view can look numerically different even when the underlying expectation is identical. For a weather market like this, fees and access matter as much as price: Polymarket is crypto-native, while Kalshi and Betfair require regulated-account onboarding and KYC, and Smarkets’ pricing usually includes exchange commission rather than a spread-only model. The main catalysts to watch are the Hong Kong Observatory’s hourly bulletins through the day, then the official daily extract after the observing day closes; if the heat persists after the 9 August record, a late-day update could still shift the highest-temperature band before settlement.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Hong Kong on August 10? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Robinhood Prediction Markets, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Robinhood Prediction Markets has a different geo footprint and routes to Polymarket's order book at 0% fees.

Are all these platforms regulated?

No. Kalshi is CFTC-regulated (US). Betfair and Smarkets are UK Gambling Commission licensed. Polymarket operates without explicit regulation — a different risk profile than a regulated sportsbook.