Highest temperature in Hong Kong on July 21?

Platform comparison

Market context

On 21 July 2026, the Hong Kong Observatory will record the day's highest temperature in degrees Celsius. Polymarket currently prices this contract at 0% YES, meaning traders are assigning negligible probability to any specific temperature band resolving. The settlement hinges on the Observatory's official "Absolute Daily Max" figure published in their Daily Extract dataset, measured to one decimal place. Resolution cannot occur until that data is finalised and published.

Hong Kong's July temperatures follow a predictable pattern shaped by the Southwest Monsoon and pre-typhoon atmospheric conditions. Historical July maxima typically range between 32°C and 35°C, with extreme heat above 36°C occurring roughly once per decade during particularly intense heat waves. The 0% pricing reflects the market's current inability to distinguish between discrete temperature bands rather than suggesting July will be anomalously cool. Comparable markets on daily temperature extremes in subtropical regions show that crowd probabilities remain heavily compressed until within 48 hours of settlement, when meteorological forecasts narrow substantially.

Traders monitoring this contract should track the Hong Kong Observatory's seasonal outlooks and any issued heat warnings as July 2026 approaches. Typhoon activity in the Western Pacific during mid-July could suppress temperatures, whilst high-pressure systems stalling over southern China would elevate them. The settlement window closes at 12:00 UTC on 21 July, after which the Observatory typically publishes daily climate data within 24–48 hours. Until the specific temperature band options are clarified on-chain, conditional token mechanics will remain illiquid.

Methodology

This page reviews Highest temperature in Hong Kong on July 21? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like PolyGram trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

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.