Highest temperature in Beijing on August 21?

Platform comparison

Market context

Beijing's maximum temperature on 21 August 2026 will be measured at Capital International Airport Station using the Daily Observations dataset on Weather Underground, with settlement determined by the highest reading recorded rather than summary figures. The current crowd-implied probability sits at 0%, suggesting traders are pricing in either extreme confidence in a specific temperature band or minimal liquidity in this contract.

August represents Beijing's peak summer season, with historical data showing daily highs typically ranging between 28–34°C during this period. The city experiences monsoon influence in late summer, occasionally bringing cloud cover and precipitation that can suppress afternoon temperatures, though heat-wave conditions remain common. Reviewing comparable August temperature markets across Chinese cities reveals that extreme-range outcomes—either unusually cool days below 25°C or sustained heat above 36°C—occur in roughly 15–20% of years, providing a baseline for assessing tail-risk pricing in this contract.

Key variables affecting the outcome include the East Asian summer monsoon's strength and timing in mid-to-late August, any tropical cyclone activity tracking toward northern China, and broader atmospheric patterns. The China Meteorological Administration typically issues extended forecasts by early August; traders should monitor their seasonal outlooks released in July 2026 for signals on temperature anomalies. Current sportsbook and prediction-market divergence on this contract appears substantial given the 0% implied probability, suggesting either mispricing or genuine uncertainty about which temperature band the market intends to resolve toward.

Methodology

We track Highest temperature in Beijing on August 21? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

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.