Highest temperature in Hong Kong on July 20?

Platform comparison

Market context

The underlying event is the peak air temperature recorded in Hong Kong on 20 July 2026, measured in degrees Celsius by the Hong Kong Observatory. This single data point will determine the market resolution, with the official figure published in the “Daily Extract” once finalized. The current crowd-implied probability of 0% YES suggests traders believe the temperature will fall outside the specific range offered, likely due to historical patterns or seasonal expectations for mid-summer in the region.

Historically, Hong Kong’s July highs typically range between 31°C and 34°C, with extreme outliers occasionally reaching 35°C or higher during prolonged heatwaves. For instance, July 2023 saw a peak of 34.6°C, while the all-time monthly record for July stands at 36.1°C in 2017 [1]. Given this baseline, a 0% probability implies the market’s range is either significantly below the expected norm or improbably high, making it a clear mismatch with climatological data. Traders evaluating this programmatically would script a fetch against the Observatory’s open API to compare real-time readings against the resolution threshold before settlement.

Key catalysts include the official publication schedule of the “Daily Extract” from the Hong Kong Observatory, which usually follows within 24–48 hours after the date. Traders should monitor the Observatory’s climate data portal for updates, as delays in data finalisation can postpone settlement [1]. Additionally, regional weather advisories from the Hong Kong Observatory regarding heatwaves or extreme heat conditions could serve as early indicators of whether the temperature will breach the market’s range. No recent news announcements specifically forecast an anomaly for 20 July 2026, so reliance remains on historical averages and real-time API validation.

Sources: 1 · 2

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Bot UK, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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 Polymarket Bot UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

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.