Highest temperature in Shanghai on August 21?

Platform comparison

Market context

Shanghai's highest temperature on 21 August 2026 will be measured at Pudong International Airport Station and resolved against the Daily Observations table on Weather Underground, with settlement occurring at 12:00 UTC that day. The market currently shows 0% implied probability across platforms, suggesting traders are either awaiting price discovery or treating this as a categorical range selection rather than a binary bet.

August temperatures in Shanghai historically cluster between 28–35°C, with extreme heat days occasionally reaching 36–38°C during peak summer. The 0% crowd probability likely reflects early-market conditions rather than a consensus forecast; comparable weather markets on Kalshi and Polymarket typically show non-zero probabilities for all temperature ranges in established markets, even for tail outcomes. Shanghai's August climate is relatively stable year-to-year, making historical data from 2015–2025 a reliable baseline for assessing which temperature bands carry realistic odds.

Traders should monitor China Meteorological Administration forecasts released in early August 2026, as these typically drive material repricing in Asian weather markets. The distinction between Weather Underground's Daily Observations table and its Day High & Low summary section matters operationally; discrepancies between the two have historically caused settlement disputes on weather contracts, so confirmation of the primary resolution source before August will be critical. Tropical cyclone activity in the Western Pacific during late summer could introduce volatility to Shanghai's temperature profile, though such systems are tracked with reasonable lead time.

Methodology

This page reviews Highest temperature in Shanghai on August 21? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to PolyGram, which mirrors the Polymarket order book at 0% fees.

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 PolyGram. 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 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 PolyGram 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.