Pronóstico: Highest temperature in Shanghai on July 4?

Platform comparison

Market context

On 4 July 2026, the Shanghai Pududong International Airport Station will record its highest daily temperature in degrees Celsius, which will determine the outcome of this prediction market. Current Polymarket pricing shows the contract is deeply skewed against the "YES" outcome for temperatures exceeding 34°C, with the frontrunner being 33°C at 29% probability and 34°C at 28%[2]. The market implies a near-zero chance of extreme heat, yet historical July averages at this station typically reach 88°F (31.1°C), rarely falling below 75°F (23.9°C) or exceeding 95°F (35°C)[1]. Recent summers in Pudong have seen spikes above 40°C, with one Sunday recording 40.4°C as the summer peak, according to the Shanghai Meteorological Bureau[7].

Traders must monitor the Shanghai Meteorological Bureau’s daily heatwave announcements and the Wunderground hourly feed for the ZSPD station, as these are the definitive resolution sources[2]. A sudden ozone plume or prolonged southerly flow could push temperatures beyond the current 33–34°C consensus, especially given that July is the hottest month with an average high of 87°F (30.6°C)[9]. The on-chain mechanics utilise USDC on Polygon with conditional tokens, meaning liquidity shifts rapidly if new forecasts suggest a heatwave[2]. Watch for any official warnings of temperatures exceeding 40°C in Pudong, as such events have previously triggered extreme price movements in similar weather contracts[7]. The settlement window closes at 12:00 UTC on 4 July, so real-time data from Wunderground will be critical for final resolution[2].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Pronóstico: Highest temperature in Shanghai on July 4? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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 Argentina. 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 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.