Highest temperature in Beijing on August 21?

Platform comparison

Market context

On 21 August 2026, the highest temperature recorded at Beijing Capital International Airport Station will fall within one of several defined ranges. In prediction markets, traders buy YES or NO shares on specific outcomes. A YES share pays out if the event occurs; a NO share pays out if it doesn't. Here, YES shares correspond to a particular temperature band—say, 32–34°C—whilst NO shares cover all other outcomes. The market's current 0% probability for YES suggests traders believe that specific range is unlikely, though the settlement window remains open until midday on the resolution date itself.

Beijing's August climate is characterised by hot, humid conditions with occasional thunderstorms. Historical data from the past decade shows daily highs in August typically range from 28°C to 35°C, with extremes occasionally exceeding 36°C during heat waves. The city experienced a notable heat event in August 2023 when temperatures reached 40°C. Understanding these seasonal patterns helps contextualise which temperature bands are plausible; ranges clustered around 30–35°C align with typical late-summer conditions, whilst outliers above 36°C or below 28°C represent less frequent but documented scenarios.

Traders monitoring this market should track China Meteorological Administration forecasts released in the weeks leading up to 21 August, as well as broader atmospheric patterns such as the East Asian summer monsoon's strength and any tropical cyclone activity in the region. The resolution source—Weather Underground's Daily Observations table from Beijing Capital International Airport Station—is publicly accessible, ensuring transparent settlement. Any discrepancy between the Daily Observations and the Day High & Low summary will be resolved in favour of the former, a detail critical for traders assessing edge cases near temperature boundaries.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

UK Frequently Asked Questions

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 Prediction Market 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.