Highest temperature in Shanghai on July 21?

Platform comparison

Market context

Shanghai’s highest temperature on 21 July 2026 will be recorded at Pudong International Airport, with the market resolving to the Celsius range containing that peak. The current crowd-implied probability for any specific outcome sits at 0% YES, yet Polymarket data shows a clear divergence: 34°C leads at 46% probability, followed by 33°C at 39% [1]. This contrast between the zero implied probability and the front-runner odds highlights a meaningful gap between prediction-market sentiment and the listed contract’s binary framing, a key detail for cross-platform odds comparison on best-prediction-markets.co.uk.

Historically, late-July highs in Shanghai typically cluster between 33°C and 38°C, with 34°C a frequent peak in recent years. Meteoblue’s forecast for Pudong Airport lists a maximum of 38°C, though it also notes a 34°C scenario under scattered clouds and thunderstorm risk [2]. The 0% YES probability likely reflects the market’s binary structure rather than a genuine belief that no temperature will occur; traders should treat the 34°C front-runner as the analyst-consensus anchor, while noting the sportsbook-style lines on Polymarket suggest stronger confidence in that range than the current contract implies.

Traders should monitor real-time updates from Wunderground, the official resolution source, and watch for sudden shifts in cloud cover or thunderstorm activity, which can suppress peak temperatures. No formal announcements are scheduled, but daily weather bulletins from Chinese meteorological services often precede significant deviations. The settlement window ends 2026-07-21T12:00:00Z, so any late-morning heat spike will be decisive. Given the 46% Polymarket odds for 34°C, the divergence from the 0% YES line presents a clear arbitrage signal for those comparing platforms.

Sources: 1 · 2

Methodology

This page reviews Highest temperature in Shanghai on July 21? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Best Prediction Markets UK, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Best Prediction Markets UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Best Prediction Markets UK trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.