Highest temperature in Shanghai on July 20?

Platform comparison

Market context

Shanghai is experiencing its peak summer heat today, with forecasts for the Pudong International Airport station indicating maximum temperatures reaching 38°C under scattered clouds and potential thunderstorms[2]. The settlement window for this weather event closes at noon UTC on 20 July 2026, capturing the day’s highest recorded degree. Current crowd-implied probability sits at 0% for the YES outcome, suggesting traders believe the specific temperature range queried is unlikely to be breached, despite the region’s characteristic muggy and sunny July conditions[3].

Historical data for mid-July in Shanghai consistently shows highs between 34°C and 38°C, framing the current zero probability as a reflection of the market’s confidence that the specific threshold will not be met[2]. When comparing platforms, Polymarket’s decimal odds format contrasts with Kalshi’s implied probability display, while Betfair and Smarkets often utilise fractional pricing for similar weather derivatives. Fee structures also diverge significantly; Polymarket typically charges lower trading fees than Kalshi, though Kalshi offers stricter KYC compliance and US regulatory oversight, which may influence liquidity depth on this specific temperature contract.

Traders should monitor real-time updates from Wunderground, the designated resolution source, for any sudden shifts in cloud cover or precipitation that could suppress temperatures below the forecasted 38°C maximum[2]. Local meteorological announcements regarding thunderstorm activity are critical, as the 70% chance of precipitation noted for this afternoon could rapidly alter the peak temperature reading[1]. Unlike traditional books that may update odds based on broader regional averages, prediction markets like Polymarket and Kalshi resolve strictly on the single station’s data, making minute-by-minute weather telemetry the primary catalyst for position adjustments before the 12:00 UTC deadline.

Sources: 1 · 2 · 3

Methodology

This page compares Highest temperature in Shanghai on July 20? 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.

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.