Highest temperature in Chengdu on August 3?

Platform comparison

Market context

Chengdu Shuangliu International Airport is on track for a hot August afternoon, and the market’s **0% YES** implies traders are effectively treating the low end of the settlement bands as the favourite. That makes sense against the local climate backdrop: August in Chengdu is typically hot, humid and rain-prone, with daytime highs around 30°C and common ranges in the low-30s rather than the upper teens or low 20s[2][8][9][11]. For a market that resolves to the day’s **highest** airport temperature, the consensus is clearly anchored to a warm outcome, but the current price suggests a strong bias against the very lowest bracket being hit.

Historically, Chengdu’s August profile gives the underdog a narrow path only if cloud cover or showers suppress the peak; otherwise, short bursts of heat can still push the day’s maximum into the low-to-mid 30s[2][3][4][6]. Forecast services for 3 August point to a mostly sunny or sunny-intervals setup, with highs clustered around 33°C to 35°C and only modest rain chances, which supports the favourite side if those projections hold[3][4][15]. The value question is therefore less about whether it is warm and more about whether the market has over-penalised the possibility of an ordinary summer high being enough to settle the relevant range.

The main catalyst is the day’s evolving forecast rather than any scheduled announcement: traders should watch for late-morning to afternoon adjustments in cloud, rain and temperature guidance, because Chengdu’s summer convection can shift the realised high by a few degrees[9][15][18]. With the settlement source tied to the airport station on Wunderground, the key dependency is the actual station observation by early afternoon UTC, not city-wide averages[2][18]. That leaves a contrarian angle on the cooler bands if precipitation lingers, but the current read still favours the warmer side of the board.

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 Who Will Win 2026. 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.

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.