Highest temperature in Shanghai on May 22?

Platform comparison

Active sub-markets

Market context

Shanghai’s airport high on 22 May will be set by the warmest reading at Pudong before the market window closes. Late May in Shanghai is usually a mild-to-warm shoulder-season period rather than a heatwave setup: long-run averages point to highs in the high teens to mid-20s Celsius, with humidity and cloud increasing as the city moves towards the wetter summer months. Recent May guidance for Shanghai has clustered around highs in the upper 70s to low 80s Fahrenheit, which translates to roughly 25-28°C, though day-to-day outcomes can vary sharply if sunshine breaks through.

That context helps explain why a 0% crowd-implied chance of the top temperature band may be too low if the city gets a clear, bright afternoon. Historical May data from Shanghai sources show repeated highs in the low-to-mid 20s Celsius, and short-term weather histories for the city have recently produced upper-80s Fahrenheit readings in mid-May, implying that the upper bands are not implausible in late spring. On Polymarket, the price is typically shown as an implied probability, while Kalshi quotes dollar prices and Betfair/Smarkets use exchange-style odds; the same temperature range can therefore look materially different once fees and commission are included. KYC access also matters: Polymarket’s reach, Kalshi’s US regulatory footprint, and Betfair or Smarkets’ exchange rules can affect who is able to participate and at what cost.

For traders, the immediate drivers are the final forecast updates for Shanghai, cloud cover at midday, and whether the local warm-up persists into the afternoon before the noon UTC settlement cut-off. If the latest forecast shows sunshine and lows in the mid-20s Celsius turning into highs near 30°C, the upper brackets gain value quickly; if marine cloud or drizzle lingers, the distribution stays anchored lower. The key comparison across platforms is not the weather itself but how quickly each book reprices that same forecast through its fee structure, liquidity, and access constraints.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Shanghai on May 22? 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

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). PolyGram routes every trade directly into Polymarket's on-chain settlement, which is why payouts land fastest.

FAQ

Is this market available outside the US?

PolyGram 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'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.