Highest temperature in Shanghai on August 18?

Platform comparison

Market context

Shanghai's highest temperature on 18 August 2026 will be recorded at Pudong International Airport Station and measured in degrees Celsius. The market resolves using Weather Underground's Daily Observations table rather than the Day High & Low summary, a distinction that matters for programmatic resolution—traders building automated settlement checkers should query the correct endpoint to avoid false positives from rounding or display discrepancies between the two data sources.

August in Shanghai typically peaks between 32–36°C, with occasional readings exceeding 37°C during heat waves. Historical data from the past five years shows that mid-August temperatures cluster around 33–35°C on average, though the 2013 heat event produced readings of 40.6°C. The current 0% crowd probability suggests either extreme confidence in a specific temperature band or insufficient liquidity across the full range. For traders evaluating this as a calibration tool, the absence of meaningful probability mass indicates the market may be underspecified or thinly traded relative to the granularity of temperature bands offered.

Monitoring China's meteorological forecasts from the China Meteorological Administration becomes actionable roughly 10 days before the settlement date. Tropical systems tracking towards the East China Sea in early August 2026 could suppress temperatures, whilst high-pressure systems anchored over the region would elevate them. Traders with API access to Weather Underground's historical station data can backtest seasonal volatility patterns and establish conditional orders that trigger if forecasts shift materially from the August climatological mean.

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 Polymarket Review UK, 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

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.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

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%.