Highest temperature in Shanghai on August 13?

Platform comparison

Market context

Shanghai's highest temperature on 13 August 2026 will be recorded at Pudong International Airport Station and resolved against the Daily Observations table on Weather Underground, with settlement in USDC on the prediction market platform. The 0% crowd probability reflects either extreme confidence in a specific temperature range or minimal trading activity; given Shanghai's consistent August heat patterns, the market may be waiting for seasonal forecasts to narrow expectations before meaningful volume emerges.

Historical August temperatures at Shanghai Pudong typically range from 32–36°C, with extremes occasionally reaching 37–38°C during heat waves. The 2013 heat wave pushed readings to 40.6°C, though such outliers remain rare. Recent summers have tracked within the 33–35°C band for daily highs. Current probability distribution suggests traders are either heavily concentrated in a narrow band or the market lacks sufficient liquidity to reflect genuine uncertainty. Comparable weather markets on crypto platforms show that temperature predictions within 2–3°C of climatological norms attract tighter spreads once forecasts solidify 7–10 days ahead.

Traders should monitor China Meteorological Administration updates and regional typhoon activity in early August 2026, as tropical systems can suppress temperatures or trigger sudden spikes. Weather Underground's data feed reliability and any station maintenance windows near the settlement date warrant attention. USDC settlement mechanics mean traders holding positions through August should track stablecoin funding rates and any platform liquidity constraints, particularly if volume spikes as the event window closes. The resolution source's explicit reliance on Daily Observations rather than summary figures creates arbitrage risk if discrepancies emerge between Weather Underground's data tables.

Methodology

Methodologically this overview focuses on on-chain pricing: Polymarket's live mid comes from the Polygon conditional-token order book and settles automatically in USDC. The other three venues — Kalshi, Betfair, Manifold — sit alongside as off-chain reference points so you can see how the contract translates across regulatory and settlement regimes.

Resolution & payout

Settlement is on-chain via UMA Optimistic Oracle. A proposer posts the outcome with a bond, a two-hour dispute window opens, then the smart contract lifts winning conditional tokens to 1 USDC and sends payments to holders' wallets automatically. No withdrawal fees beyond Polygon gas.

Off-chain venues (Kalshi, Betfair, Smarkets) settle in local fiat through bank-side clearing — faster than SWIFT, slower than on-chain. Manifold pays no real cash.

UK Frequently Asked Questions

Why USDC and not ETH or USDT?

USDC is the Polygon standard — audited reserves (Circle, monthly attestation), deepest order book, low gas costs. ETH volatility would distort probability quotes; USDT has thinner Polygon liquidity than USDC.

What does a transaction cost on Polygon?

Polygon gas is typically under $0.01 per transaction. A full trade cycle (Approve + Order + Fill) totals around $0.03 — compared to $5-50 on Ethereum mainnet.

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%.