Highest temperature in Shanghai on June 29?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded on 29 June 2026 at Shanghai Pudong International Airport, measured in degrees Celsius. Historical data shows that June highs at this station typically climb from 77°F to 83°F, rarely dipping below 69°F or exceeding 92°F, with summer peaks regularly surpassing 30°C and reaching 35°C during sunny spells[1][5]. Given that the current crowd-implied probability for a "YES" outcome sits at 0%, traders must question whether the market is mispricing the likelihood of a temperature falling within the specific resolution range, especially when comparable years show consistent warmth well above the threshold implied by a zero-probability stance.

A trader should monitor the on-chain mechanics of Polymarket, including USDC settlement on the Polygon network and the behaviour of conditional tokens, while watching for immediate weather catalysts such as forecasted light rain and thunderstorm risks for 29 June, which could suppress peak temperatures[2][6]. Recent forecasts indicate light rain and a gentle breeze with temperatures around 29°C for Monday 29th, alongside a 25% risk of thunderstorms, suggesting that cloud cover and precipitation may prevent the day from reaching the higher extremes seen in clearer conditions[2]. Traders must also verify the Wunderground resolution source directly, as the final settlement depends on the highest temperature recorded for all times on that day at the ZSPD station, making real-time data dependencies critical for accurate positioning[7].

Sources: 1 · 2 · 3 · 4 · 5

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 Polymarket Legit?. 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 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.

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.