Highest temperature in Shanghai on August 18?

Platform comparison

Market context

Shanghai's peak temperature on 18 August 2026 will be recorded at Pudong International Airport Station and measured against historical August benchmarks for the city. The crowd currently assigns zero probability to any outcome, suggesting either incomplete market formation or uncertainty about which temperature bands will be offered at settlement.

August in Shanghai typically sees daily highs between 32–35°C, with occasional peaks above 36°C during heat waves. The city's summer climate is shaped by the East Asian monsoon and proximity to the Yangtze River estuary, creating consistently warm, humid conditions. Historical data from recent Augusts shows that temperatures exceeding 37°C occur roughly once every three to five years, whilst readings below 30°C are exceptionally rare. The 0% crowd probability likely reflects traders waiting for explicit temperature brackets rather than genuine conviction that no temperature will be recorded.

Traders should monitor China's meteorological forecasts from mid-August 2026, particularly any alerts from the China Meteorological Administration regarding heat waves or typhoon activity in the Yangtze River Delta region. Tropical cyclone patterns in the Western Pacific during late summer can either suppress temperatures through cloud cover and rainfall or intensify heat through atmospheric pressure changes. The resolution methodology specifies Weather Underground's Daily Observations table at Shanghai Pudong station as the binding source, making real-time access to that specific dataset essential for settlement verification. Early market activity will likely cluster around the 33–35°C and 35–37°C bands, where historical frequency is highest.

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

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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 Who Will Win 2026. 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.

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.

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 Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.