Highest temperature in Guangzhou on July 21?

Platform comparison

Market context

Guangzhou will experience peak summer heat on 21 July 2026, with the settlement hinging on the single highest temperature reading at Baiyun International Airport Station throughout that calendar day. The 0% crowd-implied probability suggests traders are either extremely confident the market will not resolve, or that no temperature threshold has been set as the affirmative condition. Without visibility into the specific temperature range being tested, the probability reflects structural uncertainty rather than meteorological certainty.

Guangzhou's July climate is remarkably consistent. Historical data from Baiyun station shows July daily highs typically cluster between 32–35°C, with extreme readings rarely exceeding 37°C. The city's subtropical monsoon pattern produces little day-to-day volatility during mid-summer; anomalous heat waves or unusual cool spells occur infrequently. Comparable July readings from 2015–2024 establish a narrow band of expected outcomes, meaning the resolution outcome depends almost entirely on which temperature threshold the market has defined as YES.

Traders should confirm the exact temperature range specified in the market's resolution criteria, as this directly determines whether any outcome qualifies as affirmative. Baiyun station data feeds into both Wunderground and China Meteorological Administration records; minor discrepancies occasionally occur between sources. The settlement window closes at 12:00 UTC on 21 July 2026, which corresponds to early evening in Guangzhou—typically after the day's peak temperature has been recorded. No weather forecasts or seasonal anomalies currently suggest July 2026 will deviate materially from the 30-year July average for the region.

Methodology

We track Highest temperature in Guangzhou on July 21? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 Best Prediction Markets UK. 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 Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.