Highest temperature in Shanghai on August 8?

Platform comparison

Market context

Polymarket is pricing this Shanghai temperature contract at **0% YES** on USDC collateral on Polygon, which means the market is effectively saying a daily high in the target range is not expected to print on the Weather Underground observation record. The settlement source matters here: the market resolves from the **Daily Observations** table at Shanghai Pudong International Airport Station, not the higher-level Day High & Low summary, so traders need to watch the station’s observed Celsius readings rather than the headline forecast display.

For context, Shanghai’s August climate is usually hot and humid, with typical highs around **32–33°C** and lows near **25–26°C**, but extremes above the low 30s are common in some years.[6][7][9][14] AccuWeather’s Shanghai August forecast for 2026 showed daily highs in the low 80s to low 90s Fahrenheit, while Weather Underground’s live page on the morning of 8 August showed **92°F / 81°F** with a forecast high of **92°F** and a “cooler than yesterday” note.[1][3] That keeps the contract in the zone where a single hot afternoon can still matter, especially if the market’s Celsius band is tight.

A trader should watch the station’s midday and afternoon observation updates, plus any rain or thunderstorm development that caps the day’s maximum before it reaches the upper bands. AccuWeather flagged morning thunderstorms, showers, and high precipitation odds for 8 August in Shanghai, which supports the idea that cloud cover and convective rain could keep the observed maximum below forecast air-temperature peaks.[2][15] On Polymarket, the outcome is a conditional token resolution problem: USDC is locked into positions on Polygon, and the winning side is determined by whether the Weather Underground table records a top temperature inside the contract’s specified Celsius range by the settlement cutoff.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews Highest temperature in Shanghai on August 8? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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 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%.