Lowest temperature in Hong Kong on August 10?

Platform comparison

Market context

Hong Kong’s lowest temperature for 10 August will be set by the Hong Kong Observatory’s final “Absolute Daily Min” reading, which is published later in the relevant Daily Extract and is measured to one decimal place in Celsius. That matters for market design: on Polymarket the crowd-implied number is usually quoted as a straight probability, while Kalshi and Smarkets display contract pricing differently, and Betfair-style exchange markets are shaped by decimal odds and commission rather than a single yes/no probability. KYC access also differs across platforms, so the same weather outcome can trade at different effective prices depending on who can access the book and what fees are applied.

The historical context points to a mid-to-high 20s Celsius overnight low being the normal August outcome in Hong Kong, not a cool night. The Hong Kong Observatory’s 1981–2010 normals show a mean minimum of 26.3°C for 10 August, while third-party climate summaries put the historical August low around 26.7°C, reinforcing that values below the mid-20s are atypical for this date.[7][12] Recent summer conditions have also been hot: the Observatory’s August 2024 and August 2025 monthly weather reports describe exceptionally warm spells and record-breaking heat episodes, which helps explain why a 0% YES crowd price can coexist with a market that is really about whether the final minimum lands in the lowest range bucket rather than about a broadly cool forecast.[15][9]

For traders, the main catalysts are the Observatory’s overnight observations, the morning update cycle, and the eventual publication of the Daily Extract, since the contract cannot settle until that record is finalised. The near-term weather setup also matters: forecast pages show showers and overcast conditions around 10 August, with elevated rain chances but still very warm daytime temperatures, so the low will depend on whether clouds and rainfall limit nocturnal cooling or whether the air mass stays muggy through dawn.[11][1] On comparison books, this sort of contract often stays quoted in probabilities on Polymarket, but on Kalshi the same risk is translated into cents, and on exchange venues like Betfair or Smarkets the headline price can be pulled around by spread, commission, and liquidity rather than by the underlying meteorological odds alone.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Lowest temperature in Hong Kong on August 10? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

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.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Kalshi Alternative 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.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Kalshi Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.