Highest temperature in Shanghai on July 28?

Platform comparison

Market context

Shanghai's summer temperatures peak in late July, with historical daily maxima typically ranging between 32–36°C during this period. The settlement hinges on the highest temperature recorded at Pudong International Airport on 28 July 2026, sourced from Weather Underground's historical database. The 0% crowd probability suggests either extreme confidence in a specific temperature band or insufficient liquidity across the full range of possible outcomes. Programmatically, traders would benefit from automating data pulls from Weather Underground's API to cross-reference forecast models (GFS, ECMWF) against historical volatility patterns for Shanghai's summer extremes, which have occasionally exceeded 38°C during heat waves.

Historical context matters considerably here. Shanghai recorded 40.9°C in July 2022 during an exceptional heat event, though such peaks remain statistical outliers. The typical interquartile range for late-July maxima sits between 33–35°C based on thirty-year records. A trader evaluating this market should monitor whether the crowd's zero probability reflects consensus around a single narrow band or represents a data-entry artefact. Conditional order logic could be structured to trigger buys if forecasts shift toward anomalous heat patterns—tracking La Niña/El Niño indices and Western Pacific subtropical high-pressure positioning would inform such conditions.

The settlement window closes at midday UTC on 28 July 2026, creating a hard deadline for forecast updates. Any significant weather pattern shift in the preceding week—monsoon activity, tropical systems, or blocking high-pressure systems—would alter the distribution of likely outcomes. Traders with automated monitoring systems should flag any meteorological alerts from China's national weather service that might signal deviation from seasonal norms.

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.

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 Polymarket Review UK 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.