Lowest temperature in Hong Kong on July 31?

Platform comparison

Market context

Hong Kong’s early-morning minimum has already set the tone for the day: the Observatory’s July climate normals put 31 July’s average minimum at about 25.3°C under the 1991–2020 baseline, and 26.2°C under the older 1961–1990 set, so the market is effectively asking whether this morning ends up merely warm or stays unusually mild by local July standards.[6][1] The 4% crowd price for **YES** implies the market currently sees a very low chance that the final published minimum lands in the relevant target range.

Historically, Hong Kong’s July nights are sticky rather than cool, which makes a genuinely low daily minimum uncommon even before accounting for the city’s urban heat and sea-influenced climate.[7][18] Recent July cases also point to persistence in heat rather than sharp overnight drops: the Observatory said July 2023 was exceptionally hot, with a monthly mean minimum of 28.0°C, and noted that even after heavy rain on 31 July, temperatures rebounded the same day.[8] That backdrop helps explain why traders generally treat sub-25°C minima as the kind of outcome that needs a clear weather break, not just an average summer pattern.[8][12]

The immediate catalysts are the Observatory’s short-range forecasts, any overnight rain or cloud cover, and how quickly the daily extract is finalised on the climatology page after the settlement window closes.[18][2] Because the market resolves off the Observatory’s “Absolute Daily Min (deg. C)” for 31 July, the key dependency is the final official figure rather than third-party weather apps or airport-style summaries.[18][13] If there is a late update in the Daily Extract, that will matter more than intraday temperature swings, since the settlement source only becomes usable once the day’s data is published.[18]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Lowest temperature in Hong Kong on July 31? 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 Prediction Today, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 Prediction Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Today 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.