Highest temperature in Hong Kong on June 21?

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Market context

Hong Kong’s highest temperature for 21 June will be the peak reading recorded by the Hong Kong Observatory, and the market settles on the exact Celsius band containing that figure once the daily extract is published.[6][9] For a new prediction-market reader, a **YES** share pays out if the event lands in that specific band, while **NO** pays if it lands elsewhere; the current 0% YES price suggests traders see that band as effectively unreachable, not that the weather is impossible.[1]

June in Hong Kong is usually hot and humid, with the Observatory’s June records showing the month’s highest mean maximum temperatures clustered around the low 30s, including 32.4°C in June 2016 and 32.3°C in June 2015.[5] Recent market commentary on similar June temperature events has centred on a 31–33°C range, with cloud cover and showers often trimming the afternoon peak by 1–3°C, while brief clear spells can push readings a little higher.[1][2]

The main catalysts are the Hong Kong Observatory’s day-of forecast updates, any shift in rain or cloud timing, and the final published “Absolute Daily Max” in the climate extract, which is the settlement source here.[6][9] Because the market cannot resolve until the final data is posted, traders will be watching both the actual midday-to-afternoon heating window and any later Observatory updates that could alter the expected peak.[9][10]

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 Prediction Market 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

Where can I trade this market with the lowest fees?

On Prediction Market UK, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Prediction Market 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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, Prediction Market UK triggers a quick verification flow that finishes in 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.