Highest temperature in Chengdu on August 3?

Platform comparison

Market context

Polymarket is pricing this Chengdu airport temperature contract at **0% YES** today, so the market is effectively saying there is no tradeable expectation of the day’s high landing in the targeted range. The market resolves from the **highest temperature recorded at Chengdu Shuangliu International Airport Station** on 3 August, measured in Celsius, and settlements are handled through Polymarket’s usual on-chain structure: **USDC** collateral, **Polygon** rails, and conditional tokens that pay out only if the final reading falls inside the relevant bucket.

That 0% reading is hard to square with Chengdu’s August climatology. Seasonal guides put the city’s August daytime highs around **30–34°C**, with several sources noting that hotter spells can push the city and nearby areas above **35°C**[1][4][13][15]. Comparable daily forecasts for early August also cluster in the low-30s, including 3 August readings around **33°C** and, in some models, even higher[3][5][12]. In other words, the market price looks detached from the usual summer baseline, unless the contract’s range is far above the typical daily high.

For a trader, the main things to watch are the **actual airport observation** near the settlement cut-off and any intraday heat-driven spike before 12:00 UTC, because the market uses the day’s maximum, not a noon snapshot. Chengdu’s summer heat is often paired with humidity and scattered showers, which can suppress or delay peaks, but they do not remove the risk of a late-morning surge if skies clear[1][4][13][15]. Current short-range forecasts for Chengdu also point to warm conditions around the mid-30s in some outlooks, which is the key dependency for a contract tied to a single-day maximum[14].

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 Kalshi UK. 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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK 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.