Highest temperature in Chengdu on August 3?

Platform comparison

Market context

The contract hinges on the **highest observed temperature at Chengdu Shuangliu International Airport on 3 August 2026**, with the market settling to the Wunderground daily high for that station. In practical terms, that makes it a pure intra-day maximum-temperature bet rather than a forecast of the afternoon forecast headline, so any late-morning heating, brief sunshine between showers, or local station effects can matter more than the overnight low. Current crowd-implied probability is **0% YES**, which is hard to reconcile with the seasonal baseline: August is generally Chengdu’s hottest period, with typical highs around **30-32°C** and occasional peaks above **35°C** in some forecasts and climate guides.[2][6][14][16]

Comparable August readings suggest the market’s zero price is well below ordinary weather expectations. Forecast services for 3 August point to highs in the **low-to-mid 30s Celsius**, with one outlet showing **33°C** and another national-style forecast at **35°C** for Chengdu on the same date, while historical August data puts early-August highs around **29-30°C** on average.[1][13][15] That implies the relevant comparison is not whether Chengdu is warm — it is — but whether the airport station prints into the contract’s band above the market’s current implied range. On that framing, sportsbook-style lines would normally sit closer to the seasonal forecast than the present prediction-market price, so the chief divergence is between a very low crowd price and mainstream weather expectations.

Traders should watch the same-day airport forecast evolution, radar, and any rain or thunderstorm timing, because Chengdu’s August weather is humid and rainfall is common even when daytime temperatures remain high.[2][14][16] The biggest dependency is whether cloud cover or precipitation limits afternoon heating at the airport station, versus a clearer window that allows a higher daily maximum. With the settlement source tied to Wunderground history at Chengdu Shuangliu Airport, the final print will depend on the station’s recorded peak rather than citywide conditions, so even small forecast shifts near noon local time can be meaningful.

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 PolyGram. 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.

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.