Highest temperature in Shanghai on August 2?

Platform comparison

Market context

Shanghai is in its hottest period, so the market is really about whether the Pudong airport station prints a routine August high or an outlier spike. Seasonal references cluster around average daily highs in the low-to-mid 30s Celsius, with August historically Shanghai’s hottest month and occasional heatwave days reaching the high 30s or even above 40C in the city record data.[5][6][8]

That makes a 0% crowd-implied YES look more like a platform-pricing artefact than a weather view, because the event is the day’s *maximum* temperature range, not an exact-point prediction. On Polymarket, the quoted price is usually read directly as implied probability; on Kalshi, the same event would be expressed in dollar terms or equivalent odds, while Betfair and Smarkets would show decimal odds and apply exchange-style commission rather than the market-maker-style pricing common on prediction platforms. For a weather day with a late settlement cut-off, the key comparison is not whether it gets warm, but whether the highest reading crosses the range boundary that the market is using.

Traders should watch the official day-of forecast updates, because Shanghai’s August outcomes can move materially with typhoon remnants, afternoon convection, or a lingering marine layer, all of which can cap the daily maximum even when the broader month is hot.[15][17] The resolution source is Wunderground’s history page for Shanghai Pudong International Airport Station, so the relevant catalyst is the airport station’s recorded peak rather than downtown conditions or the citywide average.[10][18] If the morning forecast has already settled into a narrow high-temperature band, the remaining edge is usually around timing and cloud cover rather than a large swing in the day’s thermal regime.[10][19]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Shanghai on August 2? specifically across Polymarket, Kalshi, Betfair Exchange and Smarkets. The live probability is the Polymarket mid; the comparison columns summarise each venue's fee structure, KYC, settlement currency and payment rails. Every CTA routes to Polymarket Alternative, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Polymarket settles via UMA Optimistic Oracle on Polygon. A proposer posts the outcome with a bond, the two-hour window runs, then the smart contract pays USDC.

Kalshi settles USD through the CFTC-regulated clearinghouse — the cleanest variant, with heavier KYC. Betfair Exchange settles in account currency (GBP/EUR), net of 2-5% commission. Smarkets follows the same model as Betfair with a lower default 2% commission.

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.