Lowest temperature in Hong Kong on August 10?

Platform comparison

Market context

Hong Kong’s lowest temperature on 10 August 2026 will be set by the Hong Kong Observatory’s final daily extract, not by any intraday reading or overseas forecaster, so the contract is effectively a one-day weather-archive bet rather than a live temperature trade. With the crowd-implied probability at 0% YES, the market is pricing in an outcome in which the eventual minimum still lands outside the listed YES band; that is notably more extreme than the broader commercial-weather consensus, which points to a warm, humid August day with overnight lows in the mid-to-high 20s Celsius and daytime highs around 30°C or above.[6][10][11]

Historically, Hong Kong’s August lows are usually stubbornly high, and the climatological minimum for 10 August is cited around 26.3°C to 26.7°C in long-run normals and third-party historical datasets.[6][11] That framing matters because the observable “floor” for this market is already elevated: a normal summer night keeps the lowest reading close to the upper-20s, while any materially cooler print would generally need a rain-cooled, post-frontal, or unusual synoptic setup. In comparison terms, sportsbook-style weather lines and forecast sites are leaning warm rather than cool, so the prediction-market 0% implies a sharper bearish stance on the chance of an unusually low reading than the public forecast consensus suggests.[4][8][10]

The main catalysts are the Hong Kong Observatory’s forecast updates, the overnight evolution of showers or thunderstorms, and the timing of the final published daily extract, which is the only settlement source that matters here.[1][19] Forecasters currently show showers and overcast conditions around the date, but those are not enough on their own to force a low enough minimum unless cloud cover, rain timing, and wind keep the night from mixing out.[10][15] Traders should watch the Observatory’s regional weather text and any seasonal or short-range updates, because the market cannot resolve until the final daily data for 10 August is published and the absolute daily minimum is locked in.[1][19]

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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 Kalshi vs Polymarket 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.