Highest temperature in Shanghai on July 3?

Platform comparison

Market context

The underlying real-world event is the highest temperature recorded on 3 July 2026 at Shanghai Pudong International Airport, measured in degrees Celsius. Polymarket prices the "30°C" outcome at 37% and "31°C" at 35%, yet the specific "YES" contract for a threshold above 30°C currently sits at 0% implied probability, suggesting traders doubt the temperature will breach that level despite the frontrunner being exactly 30°C. This divergence between the leading bin and the binary threshold reflects how conditional tokens on Polygon, settled in USDC, can misprice tail events when liquidity is thin.

Historically, July is Shanghai’s hottest month, with average highs near 87°F (30.6°C) and summer peaks regularly exceeding 30°C, reaching 35°C during sunny spells [4][6]. Current on-the-ground data shows 77°F (25°C) at Pudong with mist and light showers [3], while Hongqiao reports 26°C [2]. The 0% price implies the market expects the day to remain below 30°C, a plausible outcome given the persistent cloud cover and precipitation, which historically suppress peak temperatures compared to clear-sky scenarios.

Traders should monitor the official Wunderground daily update for ZSPD, which will resolve the market at 12:00 UTC on 3 July 2026, and watch for any sudden shifts in the East South Easterly wind or pressure trends [3]. A recent AccuWeather forecast notes a morning thunderstorm with a high of 85°F (29.4°C), reinforcing the likelihood of temperatures staying just under 30°C [8]. No major weather announcements are scheduled, but the settlement depends entirely on the single daily maximum recorded, making the 12:00 UTC data release the critical catalyst for any late-position adjustments.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Kalshi UK, which mirrors the Polymarket order book directly.

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

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.

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.