Highest temperature in Guangzhou on July 9?

Platform comparison

Market context

Guangzhou will experience its peak daytime heat on 9 July 2026, with the highest temperature recorded at the Baiyun International Airport Station determining the market outcome. Historical data shows July averages near 32°C, while early July typically sees daily highs clustered between 31°C and 34°C[1][5]. Greenpeace defines days exceeding 33°C as “extreme hot days,” noting that the frequency of such events has more than doubled since the 1960s across East Asia[2]. China recently recorded its hottest July on record since 1961, with average temperatures reaching unprecedented levels[4]. In Guangzhou specifically, the city has seen its longest summer since 1961, breaking a three-decade heat record with 235 summer days measured by temperature[7][8].

Traders should monitor real-time weather updates from Wunderground, the official resolution source, as thunderstorms with heavy rain are common in July and could suppress peak temperatures[6]. The current crowd-implied probability of 0% for a “YES” outcome appears to diverge significantly from Polymarket’s frontrunner, which assigns a 40% chance to 33°C and another 40% to 34°C or higher[1]. This discrepancy suggests a meaningful gap between prediction-market implied probabilities and analyst consensus on the contract’s likely settlement range. No major weather announcements are scheduled, but the Pearl River region’s microclimate dependencies mean rapid shifts in cloud cover or rainfall could alter the day’s maximum temperature[5].

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

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

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.

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.

Do I need to KYC for this market?

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