Highest temperature in Guangzhou on July 20?

Platform comparison

Market context

Guangzhou faces its peak summer heat on 20 July 2026, with the market tracking the highest temperature recorded at Baiyun International Airport. The crowd-implied probability of 0% for a YES outcome suggests traders believe the temperature will fall outside the specific range offered, likely anticipating a value below the threshold or a data anomaly. This near-zero stance contrasts sharply with typical July climatology in the region, where daytime highs routinely exceed 33°C.

Historical data from Wunderground shows Guangzhou’s July maxima frequently land between 34°C and 37°C, with 2023 and 2024 both recording peaks above 35°C at the airport station [1]. The 0% probability implies either a mispriced range or a belief in an unusually cool day, which diverges from the analyst consensus that July 20 is among the hottest dates in the city’s annual cycle. Sportsbook lines on similar weather contracts often carry wider margins, but prediction markets here show a stark divergence from meteorological norms.

Traders should monitor the National Meteorological Centre of China’s 24-hour forecast for the Pearl River Delta, released daily at 10:00 UTC, which details cloud cover and humidity levels that suppress peak temperatures [2]. A sudden shift in the East Asian monsoon or an incoming tropical depression could alter the heat profile, though no such systems are currently forecast for 20 July. The settlement hinges entirely on the Wunderground record for ZGGG, making real-time station data the sole catalyst for resolution.

Methodology

This page reviews Highest temperature in Guangzhou on July 20? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets, which mirrors the Polymarket order book at 0% fees.

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.

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.