Highest temperature in Shanghai on August 6?

Platform comparison

Market context

Polymarket’s contract on Shanghai’s 6 August high is priced at **0% YES** today, which means traders are assigning almost no probability to the day’s maximum at Shanghai Pudong International Airport Station landing in the specified settlement band. The market settles on the highest temperature recorded at that station in Wunderground’s daily history page, so the key number is the *airport observation*, not the broader city forecast; the position is tokenised through conditional tokens and funded in USDC on Polygon, so even a small late-day shift in the forecast can matter if it changes the recorded daily maximum.

For context, Shanghai in August is typically hot and humid, with long-run guides putting daytime highs around 30–32°C and frequent rainfall, while AccuWeather’s 2026 August outlook shows highs mostly in the high 20s to low 30s Celsius and a 6 August high near 31°C in the city forecast. That makes a zero-priced contract unusual only if the market is assuming a very specific settlement bracket rather than “hot weather” generally; comparable Shanghai summer days often print comfortably above 30°C, but the airport station can still differ from city-centre forecasts because of local wind, cloud, and sea-breeze effects.

A trader should watch the Shanghai Pudong airport hourly observations and any short-term forecast updates from the morning through early afternoon, because the market resolves on the day’s peak, not the end-of-day reading. Recent forecast snapshots already show warm, sunny conditions for 6 August, with highs around the low 30s Celsius in independent weather services, so the main catalyst is whether the airport station briefly spikes above the relevant threshold before cloud cover, rain, or a marine breeze caps the maximum.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

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%.