Highest temperature in Shanghai on July 31?

Platform comparison

Market context

Shanghai is set for another very hot midsummer day, and this market settles on the highest reading at Shanghai Pudong International Airport Station on 31 July, not the citywide headline forecast. Current public forecasts cluster around the low-to-mid 30s Celsius, with AccuWeather showing 31 July highs near 91°F/33°C, Weather.com pointing to about 95°F/35°C, and the UK Met Office reaching as high as 37°C, so the market is really about whether the airport exceeds the upper-30s band or stays a little below it.[1][13][14]

The crowd’s 0% YES implies the current price is treating the top band as effectively unreachable, but that sits awkwardly with Shanghai’s normal July pattern: multiple sources describe July as the hottest month, with average highs around 29–33°C and frequent humid, unstable conditions that can still produce sharp daytime peaks.[1][7][10][19] On similar summer-temperature markets, the main reading is usually the site-specific station observation rather than the broader city forecast, which makes airport exposure, cloud cover and afternoon convection more important than generic Shanghai weather pages.[2][6]

For traders comparing platforms, Polymarket-style pricing shows a single implied probability, while Kalshi and Smarkets typically show contract prices/decimal-style odds after fees, so a “0%” look can hide a non-zero ask once spread and costs are included. Betfair often adds commission on winnings, and access differs materially: KYC and regional availability vary by venue, so the practical tradeable price can diverge from the headline probability even on the same weather event. Today’s main catalysts are the morning and early afternoon updates to Shanghai forecasts, any shift in rain or thunderstorm risk, and the live station high later in the day; if showers materialise, they can cap the maximum, while a dry, sunny afternoon can push the airport reading towards the upper end of the forecast range.[11][14]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page compares Highest temperature in Shanghai on July 31? 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

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.

Which platform has the deepest liquidity?

Polymarket — by a wide margin. Top markets reach $50-500M volume, Kalshi ~$200M cumulative, Betfair similar. Deeper liquidity means your trade moves the quote less.

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 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.