Pronóstico: Highest temperature in Shanghai on August 18?

Platform comparison

Market context

Shanghai's maximum temperature on 18 August 2026 will be measured at Pudong International Airport Station and recorded in Weather Underground's Daily Observations table, with settlement determined by which temperature range bracket contains that single highest reading in degrees Celsius. The market currently prices all outcome ranges at 0% on Polymarket, suggesting either incomplete liquidity or traders awaiting more granular pricing data before committing USDC collateral to conditional tokens on Polygon.

August represents Shanghai's hottest month climatologically, with daily highs typically ranging between 32–34°C, though extreme heat events occasionally push readings above 37°C. Historical data from the past decade shows that temperatures exceeding 35°C occur roughly once every two to three years during mid-August, whilst readings above 38°C remain rare but not unprecedented—the city recorded 40.9°C in July 2022. The 0% crowd probability suggests market participants may be waiting for seasonal forecasts or treating this as a low-conviction market until closer to the settlement date.

Traders should monitor China Meteorological Administration releases and Weather Underground's forecast updates as August 2026 approaches, particularly any alerts regarding heat waves or tropical cyclone activity in the East China Sea, which can suppress temperatures. The specific reliance on Pudong station data rather than city-wide averages means localised conditions at the airport—including tarmac heat effects and wind patterns—will determine outcomes. Settlement closes 18 August 2026 at 12:00 UTC, giving traders roughly two months from now to assess seasonal patterns and adjust positions accordingly.

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

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 Polymarket Qué Es 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.