Highest temperature in Shanghai on August 8?

Platform comparison

Market context

Polymarket is currently pricing this Shanghai heat contract at **0% YES**, so the order book is effectively saying that no listed temperature band for 8 August will end up being the highest reading at Pudong Airport in the Wunderground daily observations feed. On Polymarket, buyers hold **conditional tokens** settled in **USDC** on **Polygon**, so the market price is the crowd’s live estimate of which outcome will redeem at $1 when the 12:00 UTC settlement window closes.

The relevant context is that early-August Shanghai is normally very hot, with average August highs around **32°C** and the city’s all-time peak reaching **41°C** on 8 August 2013, which shows that extreme daytime values are entirely plausible in this window.[2][4] For comparison, historical August data for Shanghai commonly clusters in the low-30s Celsius, while some recent years have produced hotter spells, including a **35°C** August high in 2024 in one historical dataset.[3] That makes a zero-priced outcome notable, because traders are implicitly discounting a meaningful chance of a reading landing in one of the higher bands rather than only the cooler buckets.

For the final hours, the main catalysts are the same ones that move any weather market: the actual forecast into the observation period, the timing of any passing rain bands or cloud cover, and the published station readings that Wunderground records under **Shanghai Pudong International Airport Station**.[5][15] The market settles from the **Daily Observations** table, not the summary high/low panel, so a trader checking Wunderground should watch the intraday series itself rather than the headline figure. Because this is a near-dated contract, any late-day heat spike or an unexpected cooling from showers can still shift the highest observed temperature into a different resolution range before the source window closes.

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.

FAQ

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.

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.