Highest temperature in Hong Kong on July 20?

Platform comparison

Market context

Hong Kong’s highest temperature on 20 July 2026 is the real-world event this Polymarket contract tracks, with the market currently pricing a YES outcome at 0% for any temperature range above the implied threshold. On Polygon, traders use USDC to buy conditional tokens representing temperature bands, and the contract will settle only once the Hong Kong Observatory publishes its finalized “Absolute Daily Max” in the Daily Extract.

Historically, late July in Hong Kong routinely sees peak temperatures between 31°C and 34°C, with the all‑record daily maximum for the month reaching 36.1°C in 2017[1]. The 0% crowd-implied probability suggests the market expects the day’s peak to fall within the lowest listed range, consistent with the typical summer ceiling and the absence of extreme heat advisories in recent years.

Traders should monitor the Observatory’s Daily Extract release schedule, which finalises data shortly after midnight local time, and watch for any sudden heatwave announcements from the Hong Kong Meteorological Service. A recent climate update from the Observatory confirms that July 2026 has so far followed normal summer patterns, with no anomalous high-pressure systems forecast to push temperatures beyond the usual range[1]. Settlement depends entirely on this official publication; until it appears, the contract remains unresolved.

Sources: 1

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 PolyGram, which mirrors the Polymarket order book directly.

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

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.

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.