Highest temperature in Chengdu on August 20?

Platform comparison

Market context

On 20 August 2026, the highest temperature recorded at Chengdu Shuangliu International Airport will determine this market's resolution. The contract specifies reliance on Weather Underground's Daily Observations table rather than summary figures, a distinction that occasionally produces material differences in recorded extremes. Settlement occurs at 12:00 UTC on the resolution date, capturing the full diurnal cycle for that calendar day.

Chengdu's August climate presents a consistent baseline for comparison. Historical data from the past decade shows daily highs in mid-August typically ranging between 29°C and 35°C, with extreme readings above 37°C occurring in roughly one year per five. The 0% crowd probability currently assigned suggests traders are pricing in a specific temperature threshold as unlikely—likely a boundary at the upper end of the range being tested. Without visibility on which exact threshold this market covers, the nil probability indicates either a genuinely rare outcome or a misalignment between market design and participant expectations.

The primary catalyst remains the East Asian summer monsoon pattern and any anomalous high-pressure systems that might develop over central China in mid-August 2026. China's meteorological service publishes 10-day forecasts approximately one week in advance, offering the most concrete signal for traders. Recent summers have seen occasional heat waves across the Sichuan basin, though sustained extreme heat typically peaks in July rather than August. Cross-platform comparison data remains limited given the contract's specificity and forward-dated settlement, making direct odds divergence difficult to assess at present.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Best Prediction Markets, which mirrors the Polymarket order book directly.

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.

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.