Highest temperature in Hong Kong on July 9?

Platform comparison

Market context

The Hong Kong Observatory will record the absolute daily maximum temperature in degrees Celsius on 9 July 2026, resolving this prediction market to the specific range containing that figure. Currently, Polymarket prices the YES contract at 0%, implying the crowd believes the temperature will fall outside the highest range offered, likely due to expectations of a cooler-than-peak day. This on-chain pricing reflects USDC liquidity on the Polygon network, where conditional tokens are being traded based on the final data point in the Observatory’s "Daily Extract".

Historical July data frames this low probability, as average highs typically sit around 31.7°C (89°F), with peaks often reaching 33°C to 35°C during heatwaves. However, the seasonal forecast for July to September 2026 indicates temperatures will be normal to above-normal, suggesting a potential for higher readings than the current 0% pricing anticipates [1]. AccuWeather’s monthly forecast for July 2026 projects daily highs ranging from 29°C to 35°C (85°F to 95°F), reinforcing that a record-breaking day remains plausible despite the current market dismissal [3].

Traders must monitor the Hong Kong Observatory’s 9-day forecast updates and any announcements regarding typhoon activity or monsoon shifts, which could suppress temperatures significantly [6]. The primary catalyst is the finalisation of the "Daily Extract" data, which is the sole resolution source for this contract; any delay in publication will prevent settlement until the data is officially released [7]. Recent weather outlooks confirm temperatures will range between 25°C and 29°C for the immediate period, but the seasonal trend points to above-normal heat, creating a divergence between short-term forecasts and long-term expectations that a savvy trader should exploit [4].

Sources: 1 · 2 · 3 · 4 · 5

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 Kalshi 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 Kalshi 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.

Do I need to KYC for this market?

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