Highest temperature in Hong Kong on July 3?

Platform comparison

Market context

On 3 July 2026, Hong Kong will face its peak summer heat, with the Hong Kong Observatory set to record the day’s absolute maximum temperature in degrees Celsius. The prediction market currently implies a 0% chance of the temperature exceeding the highest threshold, suggesting the crowd believes the heat will stay within the lower bands. This stark consensus treats the event as a near-certainty for the underdog range, despite July being historically the hottest month in Hong Kong, with average highs around 31.7°C (89°F)[3].

Historical data frames this probability as overly cautious. July 2024 was exceptionally hot, with a daily maximum of 34.0°C recorded on a single day, one of the highest on record for moderate heat conditions[5]. Recent forecasts for July 2026 predict daily highs ranging from 35.6°C to 35.6°C (86°F to 96°F), with the average high sitting at 31.7°C (89°F)[4]. The crowd’s 0% valuation ignores these precedents, creating a potential value spot for contrarian traders betting on the favourite range, especially given that temperatures have consistently breached 32°C in recent summers[7].

Traders should monitor the Hong Kong Observatory’s “Daily Extract” releases, which finalise the absolute daily max data once published[8]. No immediate weather announcements are scheduled, but the settlement window ends on 3 July 2027 at 12:00 UTC, requiring data finalisation before resolution[1]. The key dependency is the timely publication of the climatological record, as the market cannot resolve until this data is confirmed. With recent highs hitting 35.6°C (92°F) on 2 July 2026, the contrarian angle on the favourite range appears increasingly justified[7].

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 Who Will Win 2026, which mirrors the Polymarket order book directly.

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 Who Will Win 2026. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.