Highest temperature in Hong Kong on June 20?

Platform comparison

Active sub-markets

Market context

Hong Kong is already running hot enough that the day’s peak should be set by the Observatory’s final “Absolute Daily Max” reading rather than by any intraday noise, with the live HKO tourist page showing around 30.3°C at 07:45 and a daytime range of 28–33°C alongside heavy rain risk.[1][6] For this market, the contract settles in USDC against the temperature band that contains the Hong Kong Observatory’s final daily maximum, so the key question is not whether it is warm, but whether the top reading lands inside the lower 30s or pushes into a higher bracket once the day is finalised.[6]

The 0% crowd price looks conservative relative to the seasonal backdrop. The Hong Kong Observatory’s June–August 2026 outlook calls for above-normal temperatures, while June is typically a hot month in Hong Kong with average highs around 31°C and common daily ranges in the high 20s to low 30s.[3][2] Comparable late-June heat in the city has often produced maxima close to the mid-30s, and HKO has recently highlighted a 34.3°C reading as a notable seasonal high, which is the sort of level that can move a resolution into the upper temperature bins if cloud cover and rain do not cap the afternoon.[5][6]

Traders should watch the Observatory’s 9-day forecast, the midday update cycle, and any rain or wind shifts that can suppress the afternoon maximum; HKO’s own forecast page is the direct lead indicator for how far the final reading may run.[8][6] On the crypto side, the market’s pricing will mainly reflect on-chain order flow and USDC liquidity rather than any BTC or ETH macro driver, but a thin book can still reprice quickly if spot crypto volatility, funding conditions, or whale activity push risk appetite around prediction markets broadly. The resolution itself depends only on the final HKO daily extract once published, so intraday weather rather than market chatter is the decisive input.[6]

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

Where can I trade this market with the lowest fees?

On BTC Prediction, 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?

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, BTC Prediction 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.