Highest temperature in Shanghai on July 21?

Platform comparison

Market context

Shanghai’s July heat is a relentless fixture, with the city routinely breaching 35°C during midsummer. The market on the highest temperature at Pudong Airport on 21 July 2026 currently shows a 0% implied probability for the YES outcome, suggesting the crowd believes the temperature will fall below the specified threshold. Historical data from recent Julys shows Shanghai frequently hitting 36–38°C, with 2023 and 2024 both recording peaks above 37°C on or near this date, framing the 0% price as a stark underdog bet against typical seasonal behaviour[1].

The favourite here is clearly the higher temperature range, while the 0% YES price represents a deep contrarian angle if the threshold is set conservatively low. Value may sit in backing the higher range, as the consensus appears to have mispriced the likelihood of extreme heat. Traders should monitor the upcoming week’s forecast from Meteoblue, which currently indicates a maximum of 38°C for Pudong Airport with scattered clouds and a 60% chance of precipitation, a factor that could temporarily suppress peaks but rarely eliminates them in July[3][4]. No major weather announcements are scheduled, but the daily Wunderground history will be the definitive settlement source, making real-time tracking of the 21 July reading critical as the settlement window closes at 12:00 UTC[1].

Sources: 1 · 2 · 3 · 4

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

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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 Who Will Win. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.