Highest temperature in Shanghai on August 3?

Platform comparison

Market context

Shanghai’s temperature on 3 August is likely to be set by a hot, humid summer day rather than an unusual extreme. Current forecasts for the city point to highs in the low-to-mid 30s Celsius, with sources showing roughly 32–35°C as the expected daytime peak and some predicting showers or thunderstorms rather than a cold spell.[1][3][5][7][9][16] That matters for this market because the Wunderground settlement source is the highest reading at Shanghai Pudong International Airport Station, so the key question is whether the day reaches the upper end of the forecast range or stays a degree or two lower.[13]

For framing, the current 0% implied YES price looks aggressive if you compare it with the broader August climatology, which is normally warm enough to support highs around 87–90°F, or about 31–32°C, and occasionally higher.[1][12][16] The market is therefore best read as a range question rather than a binary “hot or not” call. On platforms such as Polymarket or Kalshi, that usually means a trader can compare direct probability pricing against contract or fee differences, while Betfair and Smarkets tend to present decimal odds and take a different commission structure; the same weather outcome can therefore trade at different visible prices even when the underlying view is identical.

The main catalysts are the live forecast updates and any rain timing around the afternoon peak, because cloud cover and precipitation can cap the airport station’s maximum even in a muggy airmass.[5][7][11] Shanghai is in the summer typhoon season, so short-notice changes in convection or rain bands are the most relevant dependency for the settlement day.[9] Since the resolution source is the airport station’s daily high on Wunderground, traders should watch the latest hourly updates rather than the citywide headline forecast, as the airport can differ from central Shanghai by a meaningful margin.[13]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Shanghai on August 3? 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 Kalshi Alternative UK, 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.

Is Betfair a Polymarket alternative?

Only partially. Betfair Exchange is UK-focused with a sports-betting emphasis; they have politics markets but with thinner liquidity than Polymarket. Settlement in GBP/EUR, 2-5% commission on winnings.

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 supports Klarna/SOFORT?

Directly: none. Polymarket accepts only USDC on Polygon. Kalshi Alternative UK 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.