Highest temperature in Shanghai on August 8?

Platform comparison

Market context

Shanghai’s temperature on 8 August will be judged by the highest reading at Pudong International Airport, so the key question is whether the day tops out in the low 30s Celsius or spikes a little above that. Seasonal norms point to a very hot early-August pattern: Shanghai’s August average high is about 32°C to 32.5°C, with several sources showing typical 8 August highs around 33°C and some years reaching the mid-30s°C.[1][2][3] The current 0% YES price is therefore far below climatology, implying the market is either mispriced, inactive, or waiting for a late update rather than reflecting the usual weather profile.[1][2]

Comparable August data suggest the contract should be read as a live temperature-risk instrument rather than a broad “will it be hot?” bet. Historical and forecast tables for Shanghai repeatedly cluster near 32°C to 35°C in early August, while Weather Underground’s own history pages show recent Pudong readings around 93°F on 8 August 2026, which is roughly 33.9°C.[4][11] That sits comfortably in the upper-20s to mid-30s Celsius band where most published market ranges would likely resolve, meaning the meaningful uncertainty is not whether Shanghai is warm, but whether the airport’s official daily maximum clears the next bracket up.[4][11]

For traders, the main catalysts are the intraday temperature path, local rainfall or cloud cover, and any late-day sea-breeze or storm influence that caps the high before the settlement window closes at 12:00 UTC. Shanghai is in its hottest and most humid period in August, and multiple climate sources also flag typhoon-season volatility, which can quickly change the day’s maximum even if the morning begins hot.[8][15] In cross-platform terms, prediction-market pricing at 0% YES contrasts sharply with the seasonal evidence and with the recent Wunderground history entry, while sportsbook-style weather lines and broader analyst expectations appear to centre on a much hotter outcome than the market price implies.[4][8][11]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Shanghai on August 8? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

UK Frequently Asked Questions

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.

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.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

What are the best prediction markets for UK traders in 2026?

For UKGC-regulated markets: Betfair Exchange (sports, politics) and Smarkets (sports, politics, lower commission than Betfair). For broader global event prediction: Polymarket (deepest liquidity, 0% fee, USDC settlement). For US-regulated option: Kalshi (USD, limited UK payment options). Most serious UK traders use a combination of Betfair for regulated sports and Polymarket for broader markets.