Highest temperature in Guangzhou on August 21?

Platform comparison

Market context

Guangzhou will record its highest temperature on 21 August 2026 at Baiyun International Airport Station, measured via Weather Underground's Daily Observations table rather than the summary high-low figures. The current market pricing reflects 0% probability across all temperature ranges, suggesting traders are either awaiting historical data or treating this as a calibration exercise ahead of the 2026 summer season. On Polygon, this conditional token contract settles in USDC against whichever temperature bracket captures the daily maximum, with resolution tied explicitly to Weather Underground's primary data source.

August represents Guangzhou's hottest month climatologically, with daily highs typically ranging between 32–35°C. Historical August records at Baiyun station show extremes reaching 38–39°C during heat waves, though such peaks occur irregularly. The 0% crowd probability likely reflects uncertainty about which specific temperature band the market creator has defined rather than genuine doubt that temperatures will fall within normal August ranges. Traders should examine the exact bracket thresholds—whether they span 1°C or 5°C intervals—as this determines whether the market effectively prices tail-risk heat events or routine summer conditions.

Weather patterns for August 2026 remain unknowable at present, though seasonal monsoon activity and any developing El Niño or La Niña conditions could influence outcomes. Traders monitoring this contract should track tropical cyclone forecasts and upper-atmosphere pressure systems from June onwards, as these drive Guangzhou's most extreme heat events. The settlement window closes at midday UTC on 21 August, requiring resolution within hours of the daily maximum being recorded.

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 PolyGram, which mirrors the Polymarket order book directly.

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 PolyGram. 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%.