Highest temperature in Beijing on August 21?

Platform comparison

Market context

Beijing's highest temperature on 21 August 2026 will be recorded at Capital International Airport Station and resolved against Weather Underground's Daily Observations table. The market currently shows 0% implied probability across all temperature ranges, suggesting either incomplete pricing or settlement mechanics that require clarification before meaningful liquidity emerges. USDC settlement will occur within 12 hours of the resolution window closing at 2026-08-21T12:00:00Z.

August in Beijing typically sees daily highs between 26–32°C, with extreme heat occasionally pushing toward 35–37°C during particularly intense heatwaves. Historical data from 2010–2023 shows that temperatures exceeding 38°C occur roughly once per decade in mid-August, whilst readings below 24°C are exceptionally rare. The current flat probability distribution suggests traders are awaiting either range definitions or confidence in Weather Underground's data feed before committing capital. Comparable weather markets on crypto platforms have seen sharp repricing when seasonal forecasts update or when extreme weather warnings are issued by meteorological authorities.

Traders should monitor the China Meteorological Administration's forecasts released in late July and early August, which typically provide 10–14 day outlooks with reasonable accuracy for Beijing. Any El Niño or La Niña transitions affecting East Asian weather patterns could shift baseline expectations. Real-time atmospheric pressure and humidity data from regional weather stations will become material in the final week before settlement. Funding rates on perpetual weather derivatives across major exchanges may signal institutional positioning if large bets accumulate ahead of the resolution date.

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

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%.