Highest temperature in Shenzhen on July 21?

Platform comparison

Market context

Shenzhen's peak temperature on 21 July 2026 will be measured at Bao'an International Airport Station and resolved against historical weather data from Wunderground. The settlement window closes at midday UTC, creating a hard cutoff for the highest recorded reading across the full calendar day. For automated traders, the key technical consideration is that Wunderground's historical data updates with a lag; pulling live readings from the airport's meteorological feed directly (via China Meteorological Administration APIs) offers faster signal than waiting for the aggregator to refresh.

July in Shenzhen consistently produces temperatures in the 32–35°C range, with occasional peaks above 36°C during heat waves. The 0% crowd probability suggests either systematic underpricing of extreme heat scenarios or market participants anchoring to cooler baseline expectations. Comparable July 21st readings from prior years provide calibration: checking Wunderground's historical archive for 2015–2025 reveals the typical range and identifies years with anomalous spikes, which traders can cross-reference against broader South China heat patterns and El Niño conditions.

Monitoring tropical cyclone activity in the western Pacific during early-to-mid July becomes essential, as storm systems can suppress temperatures or accelerate them depending on timing and intensity. The China Meteorological Administration issues 10-day forecasts weekly; traders should track these alongside sea surface temperature anomalies in the South China Sea. For programmatic approaches, setting conditional orders tied to official heat warnings (issued when forecasts exceed 35°C) provides a mechanical entry point without requiring continuous manual monitoring.

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Review UK, which mirrors the Polymarket order book directly.

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

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

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.

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.

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.