Highest temperature in Guangzhou on August 21?

Platform comparison

Market context

Guangzhou's August weather remains firmly in its summer peak, with daily highs consistently exceeding 33°C throughout the month. The 21st falls within the city's hottest period, when subtropical high-pressure systems dominate and afternoon thunderstorms—though common—typically arrive after peak heating. Current crowd positioning at 0% suggests traders are pricing in either extreme confidence in a specific temperature band or insufficient liquidity to establish meaningful odds across the full range.

Historical August data from Guangzhou Baiyun International Airport shows maximum temperatures cluster between 33–36°C on most days, with readings above 37°C occurring roughly once per decade during particularly intense heat waves. The 2013 and 2015 August periods recorded several days above 36°C, whilst cooler years have seen peaks settle around 32–33°C. This distribution means the market's resolution hinges on whether August 2026 tracks toward typical conditions or an anomalous event.

Traders should monitor tropical cyclone activity in the South China Sea during mid-to-late August, as any system approaching the region would introduce cloud cover and precipitation that would suppress afternoon temperatures. Conversely, a stable high-pressure ridge with minimal cloud development would favour readings in the 35–37°C range. The China Meteorological Administration typically issues extended forecasts by mid-August; any official heat-wave warnings would signal heightened probability for the upper temperature bands. Sea-surface temperature anomalies in the preceding weeks will also influence atmospheric moisture and convective patterns.

Methodology

We track Highest temperature in Guangzhou 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 Today. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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%.