Highest temperature in Shanghai on July 25?

Platform comparison

Market context

Shanghai's summer temperatures in late July consistently exceed 30°C, with the city's humid subtropical climate producing peak afternoon readings typically between 33–37°C during this period. The settlement mechanism relies on Wunderground's historical data feed from Shanghai Pudong International Airport Station, which records hourly observations and derives daily maximum temperatures from the full 24-hour cycle. A trader automating resolution checks would need to poll the Wunderground API or parse the historical page after the settlement window closes on 25 July 2026 at 12:00 UTC, accounting for Shanghai's UTC+8 timezone offset.

Historical precedent shows July maximums at Pudong rarely fall below 32°C in recent decades. Data from 2015–2023 indicates that temperatures exceeding 38°C occur roughly once every three to four years during late July, whilst readings below 30°C are exceptionally rare—occurring only during typhoon events or unusual atmospheric conditions. The current 0% probability suggests the market may be miscalibrated or reflect an extreme scenario (such as a major typhoon system) that traders consider implausible for that specific date.

Conditional order logic should account for Shanghai's typhoon season, which peaks August–September but occasionally affects late July. Meteorological forecasts released in early July 2026 will be the primary catalyst for repricing; traders monitoring China's Central Meteorological Administration bulletins can establish trigger points for position adjustments. Real-time humidity and pressure data from regional weather stations would inform whether atmospheric conditions favour the upper or lower end of the typical range.

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

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Review UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.