Highest temperature in Shanghai on July 3?

Platform comparison

Market context

Shanghai is currently experiencing a sharp heat spike, with the Pudong International Airport station recording 86°F (30°C) at 2:30 pm today and humidity clinging to 84%, a significant deviation from the seasonal norm that typically sees early July as the coldest start to the month with highs near 24°C [1][8]. This sudden surge in temperature over the last 24 hours has overturned the market's initial 0% confidence in lower ranges, as the atmosphere has rapidly shifted from muggy cool to oppressive heat, mirroring the intense conditions that define the city's peak summer.

Historical data frames this probability shift by showing that while 3 July is usually the coldest day in the first ten days of July, extreme outliers can push daily highs to 40°C, and the last ten years have seen seven to fifteen days exceeding 35°C in July alone [3][8]. The current 42% probability assigned to 31°C and 32% to 30°C reflects traders recognising that today's 30°C reading is not an anomaly but a precursor to the typical 30–38°C daytime range that dominates Shanghai's mid-summer, making lower outcomes increasingly unlikely [2].

Traders should monitor the scheduled afternoon peak heat window around 3 pm, when temperatures historically reach their maximum, and watch for any sudden shifts in wind direction from the current 70-degree ENE flow that could alter cloud cover and precipitation [1][4]. Although no specific weather announcements are imminent, the high humidity averaging 76% this month suggests that any reduction in wind speed will exacerbate the muggy conditions, potentially driving temperatures toward the 35°C threshold that has been recorded in previous July extremes [3].

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

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.

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.

Do I need to KYC for this market?

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