Highest temperature in Guangzhou on August 15?

Platform comparison

Market context

Guangzhou will experience peak summer heat on 15 August 2026, with the highest temperature recorded at Baiyun International Airport determining settlement. The market currently prices at 0% YES across all temperature bands, reflecting the settlement window's two-year horizon and the inherent difficulty in pricing weather events so far forward. On Polygon, traders are holding conditional tokens denominated in USDC, with resolution tied to Weather Underground's Daily Observations table rather than summary figures—a distinction that matters when airport stations record multiple readings throughout the day.

Guangzhou's August temperatures have historically clustered between 32–36°C, with extremes occasionally reaching 37–38°C during particularly intense heat waves. The city's subtropical monsoon climate produces consistent summer peaks, though year-to-year variation remains substantial. August 2023 saw highs of 35–36°C across most days; August 2024 trended slightly cooler at 33–35°C. This historical range provides the baseline against which traders should calibrate their position sizing, though climate patterns shift gradually and two years allows for seasonal anomalies.

Traders monitoring this contract should track China's meteorological forecasts as August 2026 approaches, particularly any El Niño or La Niña signals that influence East Asian summer temperatures. Baiyun Airport's station records are publicly archived through Weather Underground, making post-event verification straightforward. The primary catalyst remains seasonal timing itself: August is Guangzhou's hottest month, making extreme heat more probable than other periods, yet the specific daily maximum remains genuinely uncertain at this distance.

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

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

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.

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%.