Highest temperature in Shanghai on July 3?

Platform comparison

Market context

On 3 July 2026, the Shanghai Pudong International Airport Station will record its highest daily temperature in degrees Celsius, a real-world event that determines the outcome of a Polymarket contract priced today with "30°C" as the frontrunner at 56% probability, while the "29°C" outcome sits at 27% and the "31°C" outcome at 27%[1][4]. The current crowd-implied probability of 0% for the "YES" outcome (likely meaning a specific lower threshold) appears inconsistent with seasonal norms, as July in Shanghai is historically hot and humid, with daytime temperatures typically hovering above 30°C and often exceeding 35°C, occasionally reaching 40°C[8].

Historical data from WeatherSpark confirms that daily high temperatures in July at this airport increase by 5°F, ranging from 84°F to 88°F, rarely falling below 75°F or exceeding 95°F, with the average daily high peaking at 88°F[2]. This aligns with AccuWeather’s July 2026 forecast for the station, which projects daily highs between 80°F and 93°F, reinforcing that outcomes below 29°C are statistically improbable and that the market’s current weighting of 30°C as the leading outcome is well-founded by comparable cases[9].

Traders should monitor the official Wunderground resolution source for the Shanghai Pudong International Airport Station, as the contract settles on the highest temperature recorded for all times on this day, and any sudden shifts in weather patterns—such as unexpected monsoon rains or heatwaves—could alter the final figure[1]. While no specific recent announcement has been issued, the on-chain mechanics rely on conditional tokens settled in USDC on the Polygon network, meaning liquidity and price volatility will depend on real-time weather updates rather than speculative news[1]. The settlement window ends at 12:00:00Z on 3 July 2026, so traders must watch for live temperature data leading up to that deadline to assess whether the 30°C threshold will be met.

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

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

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

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.