Highest temperature in Shanghai on May 25?

Platform comparison

Active sub-markets

Market context

Shanghai's highest temperature on 25 May 2026 will be measured at Pudong International Airport Station and resolved against historical weather data from Wunderground. The settlement window closes at 12:00 UTC on that date, meaning traders must commit before the day's peak temperature is confirmed. This market sits at 0% implied probability across the major platforms, suggesting either extreme confidence in a specific temperature band or insufficient liquidity to establish meaningful odds.

Shanghai's May climate shows consistent patterns across recent years. Historical data from Wunderground indicates May 25th temperatures typically range between 24–32°C, with occasional peaks above 33°C during warmer years. The 0% probability reading likely reflects traders' concentration in a single adjacent temperature bracket rather than genuine consensus that all other ranges are impossible. Kalshi and Betfair handle weather markets differently—Kalshi's decimal odds format and stricter KYC requirements create different entry friction than Polymarket's implied probability display, potentially explaining why this particular market shows such extreme skew. Smarkets' fractional odds presentation appeals to different trader segments, fragmenting liquidity across platforms.

Traders should monitor China Meteorological Administration forecasts from mid-May onwards, as seasonal weather patterns shift unpredictably during late spring. El Niño or La Niña conditions influence East Asian temperatures; the current phase will matter significantly. Shanghai's urban heat island effect means airport readings consistently exceed surrounding rural areas. Fee structures vary—Polymarket charges 2% on winning positions whilst Kalshi's fixed fees apply differently to weather contracts—making position sizing calculations platform-specific before committing capital.

Methodology

This page compares Highest temperature in Shanghai on May 25? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. Live odds come from the Polymarket order book; the other venues' contract details are maintained manually because their APIs aren't directly comparable. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, which mirrors the Polymarket order book at 0% fees. 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 it cost to trade on PolyGram?

Zero. PolyGram routes every order to the live Polymarket order book; the only cost is the Polygon network fee, typically under $0.01 per transaction.

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.