Highest temperature in Guangzhou on August 5?

Platform comparison

Market context

Guangzhou’s highest temperature will be set by the daytime maximum at Baiyun International Airport, and the market is currently pricing in an outcome that looks materially warmer than the present forecast suggests. AccuWeather’s August outlook shows highs around 89–93°F, or roughly 32–34°C, with 5 August listed near 92°F, while another forecast for the same day calls for heavy rain and 32°C, which would typically cap the day’s peak if the cloud cover verifies.[1][2]

That is why the 0% YES crowd price looks out of line with both seasonal context and recent market pricing. August is Guangzhou’s hottest and most humid period, with typical highs around 28–33°C and frequent monsoon showers, so a reading in the mid-30s is plausible but not guaranteed; by contrast, Polymarket’s own contract page has shown the leading bucket at 35°C, followed by 34°C and 36°C, implying traders there see a meaningful tail above the weather-site midpoint forecast.[4][8][9] In cross-platform terms, sportsbooks are not offering a meaningful line here, so the cleanest comparison is between the prediction market and the forecast models, and the market is markedly more bullish on heat than the published daily outlooks.[1][2][9]

The main catalysts are the actual cloud-and-rain evolution over the afternoon, plus any late adjustment in local forecasts as convective showers build or clear. At 11:19 UTC, AccuWeather’s radar snapshot already shows very hot conditions in Guangzhou, with temperatures around 93–94°F and shower chances in the afternoon window, which means small shifts in timing or cloud break-up could move the day’s maximum by a degree or two and change the winning bucket.[10][13] Because settlement uses the airport station’s recorded daily high, the key dependency is not citywide averages but what happens at that one reporting location before the daily cycle closes.[9]

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

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

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