Highest temperature in Beijing on August 15?

Platform comparison

Market context

Beijing's highest temperature on 15 August 2026 will be measured at the Capital International Airport Station and resolved against Weather Underground's Daily Observations table rather than the Day High & Low summary. This distinction matters operationally: the two datasets occasionally diverge due to timing of observations and data processing, so any automated resolution checker must query the correct source endpoint. The settlement window closes at midday UTC on the resolution date, creating a narrow window for final data confirmation.

Historical August temperatures in Beijing cluster between 25–35°C for daily highs, though extremes have reached 40°C during heat waves. The 0% crowd probability suggests traders are either pricing in an unusually cool day or the market lacks sufficient liquidity to establish a baseline. Comparable weather markets on similar dates show that late-summer Beijing forecasts typically narrow significantly in the 48 hours before settlement, as model consensus strengthens. Reviewing archived Weather Underground records for 15 August in prior years provides the most reliable calibration: 2023 recorded 32.8°C, 2022 reached 34.1°C, and 2021 peaked at 33.5°C.

Traders implementing conditional orders should monitor China Meteorological Administration forecasts from mid-August, which typically release 10-day outlooks by early August. Any announced heat advisory or unusual pressure system would shift the distribution rightward. Programmatically, setting up an automated data pull from Weather Underground's API on 15 August at 13:00 UTC ensures you capture the final recorded observation before settlement closes, avoiding manual lookup errors that plague weather markets.

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.

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 Polymarket Review 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%.