Highest temperature in Shanghai on May 28?

Platform comparison

Active sub-markets

Market context

Shanghai's weather on 28 May 2026 will determine which temperature band captures the day's peak reading at Pudong International Airport Station. The settlement hinges on historical data logged by Weather Underground, with the final measurement locked in at 12:00 UTC. Current crowd pricing across major platforms reflects deep uncertainty; Polymarket shows 0% implied probability on the YES side, whilst Kalshi and Betfair display comparable scepticism through decimal odds hovering near 1.01–1.02, indicating minimal conviction in any single temperature bracket. The divergence between platforms partly reflects their fee structures—Polymarket's 2% maker and taker fees versus Kalshi's tiered commission schedule—which can shift marginal positions on low-liquidity weather contracts.

Late May in Shanghai typically sees temperatures between 28–32°C, though extremes have occasionally breached 34°C during early heat waves. Historical records from 2015 and 2019 show sporadic days exceeding 33°C in late May, but sustained heat waves usually arrive in June. The current 0% reading suggests traders are either awaiting more specific temperature-range options or treating this as a placeholder market pending clarification on which brackets are actually offered.

Traders monitoring this contract should track China Meteorological Administration forecasts released in early May, which typically provide 10–14 day outlooks with reasonable accuracy. El Niño or La Niña conditions heading into northern hemisphere summer will influence whether Shanghai experiences above-average heat; the current neutral phase suggests near-normal temperatures are most probable. Settlement timing at midday UTC (20:00 Shanghai local time) captures the full diurnal cycle, eliminating any advantage from early-morning or evening readings.

Methodology

This page compares Highest temperature in Shanghai on May 28? 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 Polymarket Alternative UK, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). Polymarket Alternative UK routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

Where can I trade this market with the lowest fees?

On Polymarket Alternative UK, 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.

Is this market available outside the US?

Polymarket Alternative UK is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

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 does it cost to trade on Polymarket Alternative UK?

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

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.