Highest temperature in Hong Kong on August 5?

Platform comparison

Market context

Polymarket has this contract pricing **0% for YES** today, which means the crowd is not assigning any visible chance to the event landing in a listed temperature band. On Polymarket, traders are buying and selling conditional tokens against USDC on Polygon, so the displayed price is the market’s live estimate of the probability that the Hong Kong Observatory’s final **absolute daily maximum** on 5 August 2026 falls into that outcome range.

The main historical guide is Hong Kong’s own August climate and its sharp heat spikes. The Observatory’s normal for 5 August puts the mean maximum at **31.4°C**, but the city has also produced far hotter outcomes when a strong subtropical ridge dominates. In August 2024, Hong Kong saw an exceptionally hot spell, and the Observatory recorded **35.4°C** on 5 August, the month’s highest reading, while local reporting said the city broke its year-to-date heat record twice that day. That makes the market’s current zero bid look like a strong statement that traders think this year’s peak will stay well below extreme-humidity heatwave territory, despite August being one of Hong Kong’s hottest months.[1][3][5]

For traders, the key catalysts are the Observatory’s day-of heat alerts, the afternoon maximum before the 12:00 UTC settlement window closes, and the later publication of the finalized “Daily Extract”, which determines the official result. The contract cannot resolve until the relevant dataset appears on the Observatory’s climatology page, so a late revision or delayed release matters less for the weather itself than for when the token settles. Any pre-noon Hong Kong Observatory warning about very hot weather, or an update pointing to persistent clear skies and an upper-air ridge, would be the most direct trigger for repricing; otherwise, the market will likely stay anchored to the published bands rather than the abstract possibility of a heat record.[8][16]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on August 5? 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 PolyGram, which mirrors the Polymarket order book at 0% fees.

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 PolyGram. 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.

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.