Highest temperature in Shanghai on May 28?

Platform comparison

Active sub-markets

Market context

Shanghai's highest temperature on 28 May 2026 will be recorded at Pudong International Airport Station and resolved via Wunderground historical data. Late May sits within Shanghai's late spring period, when daily highs typically range between 28–32°C, though heat waves can push readings several degrees higher. The settlement window closes at midday UTC, meaning traders must account for the full calendar day's temperature swing before resolution.

Historical May temperatures in Shanghai show considerable year-to-year variance. Data from the past decade reveals that extreme heat days (above 35°C) occur roughly once every three to four years during this month, whilst readings below 25°C are comparatively rare. The 0% crowd probability across prediction platforms suggests either extreme confidence in a specific temperature band or minimal trading activity on this particular date. Kalshi's binary weather contracts typically attract tighter spreads than Polymarket's categorical ranges, though Polymarket's decimal odds format can obscure the implied probability distribution across multiple temperature brackets more effectively than Kalshi's fixed-odds presentation.

Traders should monitor China Meteorological Administration forecasts released in the week preceding 28 May, as subtropical pressure systems and potential typhoon activity in the Western Pacific can materially shift Shanghai's weather patterns. Wunderground's historical database occasionally shows discrepancies with official CMA records, though the platform's Pudong station data has proven reliable for settlement purposes. KYC requirements differ markedly between platforms—Polymarket operates with lighter restrictions than Kalshi in certain jurisdictions, potentially affecting liquidity distribution across these markets.

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, 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 Polymarket Alternative, 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.

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 Polymarket Alternative?

Zero. Polymarket Alternative 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.

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.