Highest temperature in Shanghai on July 3?

Platform comparison

Market context

On 3 July 2026, the Shanghai Pudong International Airport Station will record its peak temperature for the day, a real-world event that determines the outcome of a prediction market where the crowd currently assigns zero probability to the temperature staying below 29°C. This stark divergence from other platforms is notable: while one prediction market shows a 31.5% chance for the 29°C threshold, seasonal norms and historical data suggest warmer outcomes are far more likely, with July highs in Shanghai typically peaking around 3 PM and often reaching 38°C in recent years[1][3].

Historical patterns frame this probability as an outlier; July is Shanghai’s hottest month, with average highs ranging from 26–31°C and frequent daytime temperatures exceeding 35°C[1][7]. Although 3 July is statistically the coldest day in the first ten days of July, reaching only 24.3°C on average, the warmest day in the month hits 32.5°C, indicating significant volatility that contradicts the current zero-implied probability[5]. Traders should monitor the National Weather Service’s hourly updates for ZSPD, which show early morning temperatures hovering near 25–26°C, but the critical catalyst is the afternoon heatwave forecast, as light winds and moderate rain could either suppress or amplify the peak temperature[2][8]. No major weather announcements are scheduled, but the absence of a strong cooling front by midday will likely drive temperatures toward the seasonal norm, making the current market odds highly susceptible to revision.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track Highest temperature in Shanghai on July 3? 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

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 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 Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.