Highest temperature in Guangzhou on July 9?

Platform comparison

Market context

Guangzhou Baiyun International Airport will record its peak temperature for 9 July 2026, with the market resolving to the Celsius range containing that figure. The crowd-implied probability of 0% YES suggests traders believe the temperature will fall outside the specified range, yet historical data indicates early July highs typically cluster between 31°C and 34°C, making a 0% probability a stark divergence from seasonal norms[4].

Past July records show Guangzhou’s highest daily average high reaches 91°F (32.8°C) on 25 July, while low temperatures rarely dip below 26°C[1]. This summer has already seen heat waves across southern China, with July’s average temperature hitting 23.2°C—the highest since 1961—underscoring that extreme warmth is not anomalous but increasingly common[2]. The 0% market stance contradicts this trend, creating a notable gap between prediction-market odds and analyst consensus on regional heat intensity.

Traders should monitor the National Meteorological Centre’s daily heat advisories and Wunderground’s real-time station updates for the Baiyun Airport site, as sudden shifts in cloud cover or monsoon activity could alter peak readings[3]. Recent reports confirm Guangzhou has broken a three-decade heat record, with summer days measured by temperature reaching 235, reinforcing that high temperatures are the baseline expectation rather than an outlier[8]. Any delay in official data releases or discrepancies between Fahrenheit and Celsius conversions could further impact settlement clarity.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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.

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.