Highest temperature in Hong Kong on July 4?

Platform comparison

Market context

On 4 July 2026, the Hong Kong Observatory will record the absolute daily maximum temperature in degrees Celsius, with the market currently pricing a 31°C outcome at 59% probability, while the 0% YES crowd-implied figure for any alternative range reflects tight consensus on that specific threshold [1]. This contract resolves on-chain via USDC on the Polygon network, using conditional tokens that lock shares until the Observatory finalises its "Daily Extract" data for that date [1].

Historical July peaks frame this probability: the highest monthly mean maximum since 1885 was 32.9°C in July 2007, while recent records show daytime highs reaching 36.1°C in 2023 and 39°C in Sheung Shui during extreme sweltering events [2][5][8]. The current 27–32°C forecast for 3–4 July, centered on 28–29°C, aligns with typical variability but leaves room for the 31°C frontrunner to hold if scattered showers fail to suppress peak heat [1][7].

Traders must monitor the Observatory’s scheduled "Daily Extract" publication, which finalises the "Absolute Daily Max" value to one decimal place, and watch for real-time weather updates on heavy rain and cloud cover expected on 4 July [1][7]. Recent reports confirm Hong Kong recorded its hottest day of the year so far with 36.1°C, underscoring the volatility in July temperatures and the need to track live meteorological announcements before settlement [5]. The market remains dependent solely on this official data release, with no resolution possible until the extract is published.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Hong Kong on July 4? 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

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.

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.

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.