Highest temperature in Shanghai on July 9?

Platform comparison

Market context

The underlying event is the highest temperature recorded at Shanghai Pudong International Airport on 9 July 2026, measured in degrees Celsius. Historical data confirms that July is Shanghai’s hottest month, with average highs near 37°C and frequent peaks exceeding 35°C during sunny spells[5][7]. Recent forecasts for July 2026 specifically predict daily highs ranging from 36°C to 36°C, with overnight lows between 25°C and 27°C[6]. Given that the current crowd-implied probability for any temperature range is 0% YES, this suggests a market mispricing or an extreme outlier expectation, as temperatures below 30°C in mid-July at this location are historically negligible[5].

Traders should monitor real-time weather updates from Wunderground, the official resolution source, for any sudden shifts in cloud cover or precipitation that could suppress temperatures[1]. The immediate catalyst is the forecast of thundery showers and a gentle breeze for Thursday 9 July, which may lower the peak temperature compared to typical sunny conditions[3]. While sportsbooks often lag on weather-specific contracts, prediction markets like Polymarket and Kalshi offer faster odds adjustments; a divergence here implies analysts may be underestimating the cooling effect of the incoming showers[3]. No official announcements are pending, but the dependency on hourly Wunderground data means the market will react instantly to the first recorded high of the day.

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

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

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