Highest temperature in Shanghai on August 21?

Platform comparison

Market context

Shanghai's highest temperature on 21 August 2026 will be recorded at Pudong International Airport Station and measured against historical August benchmarks for the city. The current 0% implied probability reflects either extreme confidence in a specific temperature range or minimal trading activity on this particular date-range contract. August in Shanghai typically sees daily highs between 32–35°C, with occasional peaks above 36°C during heat waves; the settlement mechanism's reliance on Weather Underground's Daily Observations table rather than the Day High & Low summary introduces a technical distinction that could affect resolution if discrepancies arise between the two datasets.

Historical August temperatures at Pudong show that extreme heat (above 37°C) occurs in roughly one-third of years, whilst readings below 30°C are rare. The 0% probability suggests traders may be anchored to a narrow band, or the market lacks sufficient liquidity to reflect genuine uncertainty across all possible ranges. Polymarket's decimal-odds format and tiered fee structure differ markedly from Kalshi's binary settlement and flatter commission model; Betfair and Smarkets offer European regulatory oversight that may appeal to traders seeking KYC alternatives, though all four platforms require identity verification at higher stakes.

Traders monitoring this contract should track Shanghai's weather patterns from mid-August 2026 onwards, particularly any announced heat advisories or tropical systems that could suppress temperatures. The specific reliance on Pudong station data—rather than city-wide averages—means localised conditions at the airport become the sole resolution criterion, a detail that distinguishes this market from broader Shanghai temperature contracts on competing platforms.

Methodology

We read Highest temperature in Shanghai on August 21? from four platform perspectives: Polymarket (on-chain CLOB), Kalshi (CFTC-regulated exchange), Betfair Exchange (sports book exchange), Smarkets (peer-to-peer betting exchange). Polymarket's live mid is the canonical probability; the side-by-side columns benchmark fees, KYC, settlement currency and deposit rails so you can choose the venue that fits your jurisdiction and trade size.

Resolution & payout

Settlement is the biggest difference between the four platforms: Polymarket on-chain in USDC (instant), Kalshi USD via CFTC (T+1), Betfair and Smarkets in local currency via bank withdrawal (T+1 to T+3). On-chain settlement clears in minutes — the fastest payout path of the four.

FAQ

Polymarket vs Kalshi — which is better?

Depends on your location. Kalshi is CFTC-regulated, US-only with full KYC. Polymarket is global, on-chain, no KYC up to $1,500. Polymarket has ~10x higher liquidity but higher regulatory risk.

What does Polymarket cost vs Kalshi?

Polymarket: 0% fees, only Polygon network costs (~$0.01/trade). Kalshi: up to 7% per trade plus spread. For high-frequency traders, Polymarket is dramatically cheaper.

What about Smarkets as an alternative?

Smarkets is a UK betting exchange with a lower default commission (2%) than Betfair. Liquidity on political markets is below Polymarket, comparable to Kalshi. Geo-blocked in many jurisdictions.

Which platform is accessible globally?

Polymarket is geo-blocked in the US/UK/EU. Kalshi is US-only. Betfair and Smarkets are UK-restricted. Polymarket Alternative has a different geo footprint and routes to Polymarket's order book at 0% fees.

Which platform supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Polymarket Alternative offers a fiat on-ramp via Klarna or SOFORT (DE/AT/CH) and converts internally to USDC for the Polymarket order book. T+1 processing.