Highest temperature in Guangzhou on July 9?

Platform comparison

Market context

Guangzhou on 9 July 2026 is set to experience peak summer heat, with the highest temperature at Baiyun International Airport likely to fall between 31°C and 34°C, based on early-July historical patterns. The crowd-implied probability of 0% YES suggests the market currently expects the temperature to stay below the highest range threshold, but this contrarian stance may overlook the consistent heatwave trend that has dominated the region since 1961. Historical data shows July highs in Guangzhou typically cluster between 31°C and 34°C, with the highest daily average high reaching 33°C (91°F) on 25 July, indicating that early July is already approaching these extremes[1][4].

Traders should monitor real-time weather updates from Wunderground and any official announcements from China’s Meteorological Administration regarding heatwave intensification, as recent reports confirm Guangzhou has experienced its longest summer since 1961, with average July temperatures hitting 23.3°C—the highest since 1961[2][7]. The value spot lies in betting against the 0% consensus, given that the region has broken a three-decade heat record with 235 summer days recorded as of Wednesday, suggesting a high probability of temperatures exceeding 34°C on 9 July[8]. The underdog here is the low-probability expectation, while the favourite is the persistent heatwave pattern that has become the norm in recent years.

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

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 Who Will Win 2026. 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'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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.