Highest temperature in Hong Kong on June 21?

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Market context

Hong Kong’s highest temperature on 21 June is set by the Hong Kong Observatory’s **absolute daily maximum** in Celsius, so the practical question is whether the HKO final extract lands in a low, mid or high-30s bucket once the day is closed out. The settlement source is explicit about using the finalized Daily Extract, and the market cannot resolve until that data is published[7][4].

A 0% YES crowd price is usually read as either a stale book, a missing event flow, or a threshold market where traders expect the realised maximum to fall outside the current YES range. That matters here because Hong Kong has already produced June extremes well above 32°C, with the Observatory’s June rankings showing monthly mean maxima around 31.6°C to 32.4°C in the warmest historical Junes[2]. Recent reporting also shows the city can spike sharply, including a 36.1°C reading that marked the hottest day of the year in one recent heatwave, and a 34.6°C hottest-day print in another case[1][5].

For programmatic trading, the useful inputs are the HKO hourly updates, any heat-related advisories, and the publication timing of the Daily Extract rather than the intraday headline alone. Hong Kong summer-solstice cases have previously matched 34°C, with local media noting subtropical ridge conditions driving the day’s peak[6]. A bot or conditional order setup would typically watch for morning and afternoon maxima, then wait for the HKO’s final daily table before reconciling whether the outcome lands in the selected temperature range[7][4].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on June 21? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at Polymarket Bot UK — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

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 Bot UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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.