Highest temperature in Shanghai on August 21?

Platform comparison

Market context

Shanghai's highest temperature on 21 August 2026 will be measured at Pudong International Airport Station and recorded in Weather Underground's Daily Observations table, with settlement determined by the most granular data available rather than summary figures. The current market pricing reflects zero probability across all temperature bands, a positioning that suggests either extreme confidence in a specific outcome or minimal trading activity establishing a floor. On Polygon, this conditional token contract settles in USDC once Weather Underground publishes its official station data for that date.

August in Shanghai typically peaks between 32–35°C, with occasional days exceeding 36°C during heat waves. Historical records show that extreme heat events—temperatures above 37°C—occur roughly once every two to three years during summer months, whilst readings below 30°C are rare for mid-August. The 0% crowd probability may reflect uncertainty about which specific temperature band the market has priced, or it could indicate that traders are awaiting clearer atmospheric forecasting models before committing capital to any single range.

Traders monitoring this contract should track China Meteorological Administration updates and seasonal typhoon activity in the Western Pacific, both of which influence Shanghai's August weather patterns. The China National Weather Service typically issues extended forecasts 10–14 days ahead, providing the most actionable signal before settlement. Any tropical cyclone formation near the Philippine Sea could suppress temperatures significantly, whilst high-pressure systems over eastern China would push readings toward historical highs. Settlement occurs at 12:00 UTC on 21 August 2026, giving traders a defined window to monitor real-time station data as it publishes.

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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%.