Lowest temperature in Hong Kong on August 5?

Platform comparison

Market context

Hong Kong’s lowest temperature on 5 August will be the Hong Kong Observatory’s recorded daily minimum, published later in the official Daily Extract and measured to one decimal place. In practice, that makes this a tight call between adjacent buckets: the market is currently pricing **27°C** as the leading outcome, with **26°C** next, and the Polymarket page says the current forecast is for overnight lows of **26–27°C** under cloudy skies with scattered thunderstorms linked to a broad monsoon trough.[1]

That positioning fits Hong Kong’s August climatology, where tropical heat and humid nights usually keep minima elevated even when rain trims daytime peaks. The observatory’s own August 2025 summary shows the month’s lowest reading was **24.0°C** on 5 August, set during persistent downpour, which is a reminder that a rain-heavy setup can still pull the daily floor down several degrees if cloud cover and showers persist through the night.[16] For comparison, the current crowd-implied **0%** on the “YES” side is also easier to read on Polymarket than on an exchange-style book: Polymarket quotes direct implied probability, while Kalshi and Betfair typically surface contract or odds pricing after fees, and Smarkets-style books usually make the fee drag more explicit at the margin.

For traders, the main catalysts are the Hong Kong Observatory’s short-range updates, any late shifts in the monsoon trough or thunderstorm timing, and the eventual publication of the official Daily Extract, because only the HKO figure counts for settlement.[1][6] The market also notes that later revisions to already-published temperatures will not affect resolution, so the key dependency is the first finalised record for that date rather than any retrospective adjustment.[1] On a platform-comparison basis, access and pricing friction matter here: Polymarket is crypto-native and typically easier to trade where available, whereas Kalshi’s KYC and jurisdiction rules are stricter, Betfair uses decimal odds and exchange matching with commission, and Smarkets generally sits closer to an exchange model with transparent charges.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We read Lowest temperature in Hong Kong on August 5? 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

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

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.

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.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket 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.