Highest temperature in Guangzhou on July 21?

Platform comparison

Market context

Polymarket currently prices this contract at 0%, reflecting near-total certainty that Guangzhou's peak temperature on 21 July 2026 will fall outside whichever range this market settles to. The settlement hinges on the highest reading recorded at Guangzhou Baiyun International Airport Station that day, pulled from Wunderground's historical database and measured in Celsius. Traders holding USDC on Polygon will receive conditional tokens representing their chosen temperature bracket, with payouts determined by which range captures the actual high.

Guangzhou's July climate is remarkably consistent. Historical data from the airport station shows July highs typically cluster between 32–35°C, with extreme readings rarely exceeding 37°C or falling below 31°C. The city's subtropical monsoon pattern, combined with urban heat island effects, produces narrow seasonal variance. Comparable years suggest the probability mass should concentrate heavily in the 33–36°C bands; the current 0% pricing on all ranges indicates either a technical issue with market initialisation or extreme illiquidity preventing rational price discovery.

Traders should monitor China Meteorological Administration forecasts released in early July 2026, which typically provide 10-day outlooks with reasonable accuracy for regional maxima. Tropical cyclone activity in the South China Sea during mid-July could alter atmospheric conditions and introduce volatility to otherwise predictable patterns. The settlement window closes at midday UTC on 21 July, giving traders roughly 12 hours after local sunrise to adjust positions based on morning weather reports and observed temperatures from comparable stations.

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.