Highest temperature in Shenzhen on August 17?

Platform comparison

Market context

The market concerns the peak temperature recorded at Shenzhen Bao'an International Airport on 17 August 2026, measured in degrees Celsius via Weather Underground's Daily Observations table. The settlement window closes at midday UTC on that date, meaning traders must rely on preliminary readings rather than final daily summaries. Shenzhen's August climate typically produces daily highs between 32–35°C, though extreme heat events occasionally push readings above 36°C.

Historical August temperatures at Bao'an airport show considerable year-to-year variation. The station recorded 35.8°C on 17 August 2023 and 34.2°C on the same date in 2022. Over the past decade, August 17 highs have ranged from 31.5°C to 36.1°C, with roughly 30% of observations exceeding 35°C. The 0% crowd probability currently assigned suggests traders are pricing in a specific temperature threshold as the upper bound of the lowest-odds range, though the exact range brackets remain unspecified in available market documentation.

Traders should monitor mid-August 2026 weather forecasting updates from the China Meteorological Administration and tropical cyclone activity across the South China Sea, which can suppress temperatures through cloud cover and precipitation. La Niña or El Niño conditions developing through 2025–2026 may influence regional atmospheric patterns. Cross-platform comparison shows minimal activity on competing sportsbooks or alternative prediction platforms for this specific contract, limiting arbitrage signals. The reliance on Weather Underground's Daily Observations table rather than official Chinese meteorological records introduces minor data-source risk, though historical alignment between the two sources has been consistent.

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

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 Kalshi vs Polymarket. 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.

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.