Highest temperature in Hong Kong on July 20?

Platform comparison

Market context

Hong Kong faces its peak summer heat today as the city monitors the highest temperature recorded on 20 July 2026, with the Hong Kong Observatory set to publish the definitive daily maximum in degrees Celsius. The prediction market currently shows a 0% implied probability for the YES outcome, suggesting the crowd believes the temperature will fall outside the specific range offered, despite the region’s typical July highs often exceeding 33°C.

Historical data from the Hong Kong Observatory reveals that July 20 has frequently registered temperatures between 33°C and 35°C in recent years, with 2018 and 2022 both hitting 34.5°C under similar humid, stagnant conditions [1]. This pattern contrasts sharply with the current market pricing, which implies an outlier cool day or a range mismatch, as comparable dates in the last decade rarely dipped below 32°C even during brief rain showers.

Traders should watch the Observatory’s upcoming “Daily Extract” release, which finalises the “Absolute Daily Max” figure and triggers market settlement before the 12:00 UTC deadline on 21 July [2]. No immediate weather announcements are expected to alter the reading, but the timing of the data publication remains the sole dependency, with any delay potentially extending the resolution window beyond the current settlement timestamp.

Methodology

We track Highest temperature in Hong Kong on July 20? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 Best Prediction Markets. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

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.