Highest temperature in Hong Kong on June 21?

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Market context

The day’s settlement will hinge on the Hong Kong Observatory’s final **“Absolute Daily Max (deg. C)”** for 21 June, with the market paying USDC on the temperature band that captures that figure once the daily extract is published.[7] June is already Hong Kong’s warm season, and the Observatory’s climate data show that the city’s June maximums can sit in the low-30s, with the highest monthly mean maximum temperature on record reaching 32.4°C in June 2016.[3]

That matters for reading the current **0% YES** crowd price: the distribution of comparable June outcomes is not tightly clustered around a single point, and small shifts in cloud cover, monsoon flow, or afternoon rain can move the day’s peak by several degrees. Polymarket’s own market snapshot shows traders have recently concentrated around the **32°C** and **33°C** bands, which fits the historical tendency for Hong Kong June highs to land in the upper-20s to low-30s rather than at extremes.[1][3] Hong Kong has also produced much hotter late-spring and summer readings in past years, including a 36.1°C maximum on one recent record day, so the upper tail is credible when synoptic conditions align.[2]

For traders, the main catalysts are the Observatory’s day-ahead and intraday forecasts, any shift in the southwest monsoon, and the timing of the final HKO daily extract, which is the only source that settles the contract.[4][7] Because the market resolves on the published Celsius value rather than on live exchange prices, the key on-chain variable is whether late positioning builds around a particular band as weather updates narrow the range. Crypto-wide moves can still matter at the margin by changing liquidity and risk appetite across prediction markets, but the contract itself is driven by Hong Kong’s official temperature reading, not BTC or ETH price action.[5]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — are listed with their platform attributes, because they operate off-chain and a 1:1 comparison of contract mechanics isn't possible.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

FAQ

Is this market available outside the US?

BTC Prediction 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.