Highest temperature in Hong Kong on July 7?

Platform comparison

Market context

On 7 July 2026, Hong Kong will face its peak summer heat, with the Hong Kong Observatory recording the absolute daily maximum temperature in degrees Celsius. The market currently implies a 0% probability for the "YES" outcome, suggesting the crowd believes the temperature will fall outside the specified range. This extreme consensus treats the event as an underdog, yet historical data reveals July is consistently Hong Kong’s hottest month, with mean maximums near 31.8°C and frequent spikes above 34°C[4][8]. For instance, on 7 July 2025, the Observatory recorded 34.3°C, a figure that aligns with typical July peaks where temperatures often reach 35°C across the city[9].

Traders should monitor the Hong Kong Observatory’s final "Daily Extract" publication, which is the sole resolution source and may lag by several days after the event[4]. Recent climate reports confirm July 2025 was the city’s hottest month on record, with the highest number of hot days since 1884, reinforcing the likelihood of extreme heat in July 2026[8]. While the crowd dismisses the range, the value may lie in contrarian positions given the historical tendency for July highs to exceed 34°C, a threshold frequently breached in recent years[3][9]. The settlement window ends 12:00 UTC on 7 July 2026, but data finalisation depends entirely on the Observatory’s official release schedule[1].

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

FAQ

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.

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.