Highest temperature in Shenzhen on July 21?

Platform comparison

Market context

Shenzhen faces its peak summer heat on 21 July 2026, with the market tracking the highest temperature recorded at Bao’an International Airport in degrees Celsius. The settlement relies on Wunderground’s daily history for the ZGSZ station, capturing the day’s maximum reading regardless of the hour. Current crowd-implied probability sits at 0% YES, suggesting the market expects the temperature to fall outside the defined range, though historical July peaks in Shenzhen routinely exceed 35°C.

Historical data for late July in Shenzhen shows maximum temperatures frequently reaching 36–38°C at Bao’an Airport, with extremes occasionally hitting 39°C under clear, humid conditions. A 0% YES probability is anomalous for a summer heat market unless the range is set well above typical maxima, such as 40°C or higher. Programmatic traders should back-test Wunderground’s ZGSZ archive for the past five years to confirm the distribution of July 21 highs and validate whether the current pricing reflects a genuine outlier or a mispriced range.

Key catalysts include the official release of the day’s Wunderground history, which settles the market at 12:00 UTC. Traders monitoring this via API should watch for real-time updates from AccuWeather or NOAA’s ZGSZ timeseries, which may flag anomalies before the final record is logged. While no specific weather announcements are pending, sudden shifts in cloud cover or humidity—observable via live feeds like AccuWeather’s RealFeel data—could signal whether the day will breach the upper threshold. The dependency on a single resolution source means automated strategies must prioritise data latency and error handling around the settlement window.

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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 Fees. 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 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 Kalshi Fees 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.