Highest temperature in Shanghai on August 18?

Platform comparison

Market context

Shanghai's maximum temperature on 18 August 2026 will be measured at Pudong International Airport Station and recorded in Weather Underground's Daily Observations table. The market currently prices all temperature ranges at 0% YES, indicating either a data lag or settlement uncertainty rather than genuine confidence in any particular outcome. Traders are effectively pricing this contract as unresolved pending the actual date and subsequent data publication.

August in Shanghai typically sees daily highs between 32–35°C, with occasional peaks above 36°C during heat waves. Historical data from the past five years shows that mid-August temperatures have ranged from 31°C to 37°C, with 2020 and 2022 recording notably elevated readings. The 0% probability across all ranges suggests the market may be awaiting the settlement window or reflects thin liquidity rather than a genuine forecast. Comparable weather markets on Polymarket show similar pricing patterns before the resolution date approaches, with probability mass shifting sharply once actual observations become available.

Traders should monitor China Meteorological Administration forecasts and any typhoon activity in the Western Pacific, as tropical systems can suppress temperatures significantly. The settlement mechanism's reliance on Weather Underground's Daily Observations table—rather than the Day High & Low summary—introduces a specific data dependency; discrepancies between the two sources have historically caused resolution disputes. USDC conditional tokens on Polygon will settle once the highest recorded temperature is confirmed, typically within 24–48 hours of the observation date.

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 Scam?, 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

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.

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%.