Highest temperature in Shanghai on August 1?

Platform comparison

Market context

Polymarket prices this Shanghai airport temperature contract at **0% YES** today, so the market is effectively saying the current on-chain USDC, Polygon-position is assigning no weight to the event clearing the listed temperature range. Because settlement uses the highest temperature recorded at Shanghai Pudong International Airport Station on 1 August, the trading question is not whether Shanghai is “hot” in general, but whether the day’s peak lands inside the specific bucket that matches the Wunderground history feed.

For context, August is Shanghai’s hottest month on most climate summaries, with typical highs around 32°C to 35°C and occasional spikes far above that range. Recent and historical references show that Shanghai can still post extreme August maxima, with record readings reaching about 40°C to 41°C in the city’s weather histories, while 2025 saw a high of 39.5°C on 24 August. That makes the distribution skewed towards warm outcomes even when the market is currently discounting them.

A trader watching the tape should focus on the day’s forecast evolution, especially any heatwave advisories, changes in cloud cover or rainfall timing, and the strength of afternoon convection near Pudong airport, because the settlement source is the station’s highest observation rather than a citywide average. In practice, the most relevant catalysts are updated forecasts from major weather services and any late-morning or early-afternoon shift in expected maxima before the 12:00 UTC settlement window closes.

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

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.

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.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Kalshi UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.