Highest temperature in Hong Kong on July 1?

Platform comparison

Market context

The Hong Kong Observatory will record the absolute daily maximum temperature in degrees Celsius on 1 July 2026, resolving whether it hits 33°C. On Polymarket, this contract trades at 0% YES for the 33°C outcome, a stark divergence from the 54.5% probability seen on Lines.com following a sharp overnight repricing [1]. This on-chain pricing, settled in USDC on the Polygon network via conditional tokens, reflects a market that has effectively priced out the heat spike, despite the underlying meteorological reality suggesting otherwise.

Historical July data frames this 0% probability as highly anomalous. The Hong Kong Observatory’s seasonal forecast for July to September 2026 anticipates normal to above-normal temperatures [2], while AccuWeather projects daily highs between 85°F and 93°F (roughly 29°C to 34°C) for the month [3]. Traveloka confirms the average July temperature sits between 28°C and 32°C, with 31°C being a typical daytime peak [6][8]. Given that 33°C is only 1°C above the average high and well within the forecasted range, the current crowd-implied probability of zero ignores the consistent thermal patterns of Hong Kong’s peak summer.

Traders must monitor the Hong Kong Observatory’s "Daily Extract" for the finalized "Absolute Daily Max" reading, as the market cannot resolve until this data is published [1]. The immediate catalyst is the regional weather update for 1 July, which currently forecasts sunny periods with a few showers and temperatures ranging from 28°C to 33°C [7]. Any sudden shift in the south China weather outlook, such as the unexpected drop to 13°C mentioned in recent social forecasts, would be a critical dependency to watch, though current official guidance supports the higher end of the temperature spectrum [4]. The settlement window closes on 1 July 2026 at 12:00 UTC, locking in the final observational data.

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 Kalshi UK, which mirrors the Polymarket order book directly.

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

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 UK. 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.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

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.