Highest temperature in Hong Kong on August 3?

Platform comparison

Market context

Hong Kong’s highest temperature on 3 August will be the Hong Kong Observatory’s recorded daily maximum in Celsius, published after the day closes. For a programmatic trader, the key is that settlement depends on the final **“Absolute Daily Max (deg. C)”** in the Observatory’s daily extract, so the practical task is to watch the source file rather than extrapolate from live point readings alone.[12][2]

The market currently assigns 0% to YES, which is inconsistent with Hong Kong’s August climate and recent examples of extreme heat. The Observatory’s August normal daily maximum for 3 August is 31.4°C, and the city has recently logged much hotter outcomes, including 34.3°C in 2025 and 35.4°C during an exceptionally hot spell in August 2024.[4][11][5] That makes sub-30°C and low-30s outcomes structurally less likely in a typical Hong Kong August regime, even though the exact daily outcome still depends on cloud, rain and the passage of weather systems.[4][5]

For traders using tools, bots or conditional orders, the main catalysts are the Observatory’s hourly updates, any tropical-cyclone-related advisories, and the timing of the final daily extract publication, because the market cannot resolve until the dated record is finalised.[10][12][2] At 2 p.m. Hong Kong time on 3 August, the Observatory was already reporting 30°C at the station, with many other districts around 27–30°C, which gives a live benchmark for intraday repricing if afternoon heating continues or cloud cover limits the peak.[10]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Review UK, which mirrors the Polymarket order book directly.

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 Polymarket Review UK. 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.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.